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(SportsNetwork.com) - The 2013 incarnation of the San Diego Chargers might have been the biggest surprise in the NFL.

After a 7-9 campaign, and more confounding mediocrity from Philip Rivers, the Bolts cleaned house. Tom Telesco was named general manager and the Chargers hired Mike McCoy, formerly the offensive coordinator of the high-powered Denver Broncos, as the head coach.

The task was McCoy's to finally maximize Rivers' talent and minimize his mistakes. Early on, the job proved daunting as the Chargers began 5-7, but four straight victories, and a little luck, propelled San Diego into the postseason for the first time since 2009.

The Chargers toppled the Cincinnati Bengals on the road in the wild-card round, then came within a touchdown of the Broncos in Denver, no small feat.

This go-around there will no sneaking up on the league. In arguably the toughest division in the AFC, the Chargers will face a more difficult schedule and expectations for postseason improvement.

"I just think we know what to expect now," Rivers said. "You just want to keep fine tuning the details and all the little things, Every little thing matters and it's not relaxing on anything. I think our whole offense, our whole team has that mindset."

Rivers is a gigantic reason why the Chargers not only made the postseason, but also believe a deeper run is possible.

Last season, Rivers finished fifth in passing yards, fourth in touchdown passes and threw only 11 interceptions. The five-time Pro-Bowler improved significantly in all three categories.

The offense is solid, especially with some young skill players emerging last season, or poised to emerge this one.

The defense needed some work.

Injuries hampered several key pieces on the Chargers, but the defensive unit finished in the bottom-third in yards per game and posted the fourth-worst passing yards per game average.

San Diego addressed the need for improved play against the pass with first- round draft pick, Jason Verrett. He is a good cover guy and can play the run. Verrett's only crime is that he stands 5-feet, 10 inches tall, which is small by today's NFL standards.

The Bolts also upgraded the secondary with the signing of Brandon Flowers. It didn't hurt that the Chargers pilfered him from division rivals, the Kansas City Chiefs.

"He really is a true professional," defensive coordinator John Pagano said of the former Pro-Bowl corner. "He comes to work every day and tries to pick everything up with the terminology. He's focused and wants to be the very best at his position, which you love to see."

Flowers has been banged up during training camp, but nothing too serious. In fact, a lot of Chargers' defensive personnel, especially on the line, have been injured this summer. A healthy unit is essential for San Diego's postseason aspirations.

The defense showed improvement as last season played out. Including their two playoff games, the Chargers allowed an average of 17.4 points over their final seven games. Twice, San Diego held the Broncos under 25 points during that span. That is impressive, but this group has to hold up its end for the Bolts to have a legitimate shot at advancing further in the postseason.

The Chargers got into the playoffs the final week of the 2013 season. It was close to the perfect storm. Three teams from the AFC West made the postseason last year. San Diego will have to work hard for a postseason berth. The Chargers don't have the talent of either the Broncos or the Chiefs.

Most playoff teams don't need significant improvement to keep pace. The Chargers may be the exception to that rule.

2013 RECORD: 9-7 (3rd, AFC West)

LAST PLAYOFF APPEARANCE 2013, lost to Denver Broncos in AFC Divisional Playoff

HEAD COACH (RECORD): Mike McCoy (9-7 in one season)

OFFENSIVE COORDINATOR: Frank Reich (second season with Chargers, 1st as OC)

DEFENSIVE COORDINATOR: John Pagano (13th season with Chargers, 3rd as DC)

KEY ADDITIONS: CB Brandon Flowers (from Chiefs), CB Jason Verrett (first round, TCU), QB Kellen Clemens (from Rams), RB Donald Brown (from Colts), G Chris Watt (third round, Notre Dame), LB Kavell Conner (from Colts), CB Brandon Ghee (from Bengals)

KEY DEPARTURES: OC Ken Whisenhunt (to Titans), CB Derek Cox (to Vikings), G Stephen Schilling (to Seahawks), NT Cam Thomas (to Steelers), QB Charlie Whitehurst (to Titans), RB Ronnie Brown (to Texans), FB Le'Ron McClain

QB: Rivers returned to the Pro Bowl last year thanks to a career-best completion percentage of 69.5. His 4,478 yards passing was tops since 2011, his 32 scoring passes were his most since 2008 and his 11 interceptions were his lowest mark since 2009. Rivers posted a passer rating of 105.5, which matched his best.

There will be something of an adjustment for Rivers. Offensive coordinator Ken Whisenhunt left the Chargers to become the head coach of the Tennessee Titans and was replaced by quarterbacks coach Frank Reich. However, McCoy is an offensive-minded coach, so the switch at coordinator might not impact Rivers too greatly.

With this being McCoy's second year at the helm, Rivers still has some learning to do when it comes to the playbook. McCoy indicated Rivers, 32, still has room to improve since the Chargers didn't utilize the full playbook last season.

Rivers is just happy to see himself and his organization return to relevancy.

"Over the last few years you realize you're not going to do this forever and I never have taken it for granted," he said. "You enjoy every element. You enjoy the locker room, enjoy the practice field, enjoy the meetings, you just appreciate what we get to do. We're a bunch of young men that get to be on a team playing football so I think it's just really appreciating that and then fighting like crazy to try to win a championship."

Rivers has a new backup this year with Kellen Clemens coming over from the St. Louis Rams. Charlie Whitehurst bolted for Tennessee with Whisenhunt.

GRADE: B+

RB: Simple mathematics told us that Ryan Mathews played all 16 games in a season for the first time in his career. Consequently, Mathews rushed for a career-best 1,255 yards and finished seventh in the league.

Mathews answered a lot of questions about his toughness in 2013 as he also battled hamstring and ankle injuries. Durability was an issue for Mathews, but he came in fourth in the NFL in rushing attempts with 285. It's easy to forget about Mathews since he's seen in the trainer's room more frequently than a roll of athletic tape, but he's only starting his fifth season. There isn't a ton of tread on his tires.

Mathews' receiving numbers dipped from years past, but that probably had more to do with Danny Woodhead. The diminutive pass-catcher grabbed 76 balls last year for 605 yards, making him one of the most productive backup running backs in the league.

The Chargers hedged their bet about Mathews' health by signing Donald Brown to a three-year contract in the offseason. Brown is decent enough, but never lived up to his first-round selection by the Indianapolis Colts.

GRADE: B

WR: If the Chargers were one of the biggest surprises in the NFL last year, Keenan Allen has to be one of the biggest reasons why. The second-year man finished with 71 catches for 1,046 yards (both franchise rookie records) and eight touchdowns. That's preposterous production for the third-round pick, and expectations won't be tempered in his sophomore season.

Allen is already emerging as a leader in the receiving corps, a position he's embracing.

"I'm just trying to keep building everyday and keep the chemistry strong," Allen said. "Keep it going with the guys and just try to get better."

Malcom Floyd is a name to remember. He missed almost all of last year with a neck injury, but in his two previous healthy seasons, Floyd averaged 49.5 catches, 835 yards and five touchdowns.

Eddie Royal should be back in the slot and Vincent Brown should continue to develop into a capable receiver.

GRADE: B

TE: Antonio Gates is most likely headed to Canton.

Are his best days behind him? Of course. Father Time is undefeated and Gates is 34, heading into his 12th season in the league.

Before we kick dirt on Gates' career, examine his numbers from the 2013 campaign. Gates caught 77 passes for 872 yards, both of which represented his highest output since 2009. His touchdown numbers shriveled to four, which was his fewest trips to the end zone since his rookie year in 2003.

However, Gates remains a viable weapon for Rivers, McCoy, Reich and San Diego faithful.

Ladrarius Green enters his third season. He made a mark in his second season with three touchdown receptions. Green seems ready to shoulder a bigger load for the offense.

GRADE: B

OL: This group showed serious improvement last year as evidenced by Mathews' rush total, but also by how many times Rivers stayed upright. Rivers was sacked 30 times, which was down from 49 the year prior.

D.J. Fluker, the team's 2013 first-round pick, stabilized the right-tackle position and King Dunlap, who came over as a free agent from the Philadelphia Eagles before last year, did a nice job on the left side.

Nick Hartwick is more dependable than a sunrise in the center spot.

Chad Rinehart should have a stranglehold on the left guard spot. He signed a two-year extension in March after rejuvenating his career in California.

The right guard spot is still in something of limbo. Incumbent Jeromey Clary is on the physically inactive list thanks to hip and ankle surgeries in the offseason. Clary made a wise decision in restructuring his contract down to $1.6 million, which allowed San Diego some financial wiggle room.

Clary hopes to be ready for the season opener on Sept. 8. If he can't be, there has been a battle between rookie third-round pick Chris Watt and Johnnie Troutman for the right guard spot.

GRADE: B-

DL: This group was banged up during the regular season and has been during the preseason as well.

Corey Liuget is a potential Pro Bowler in waiting, but he's been nursing an ankle injury throughout camp. That comes after offseason shoulder surgery. When Liuget is right, he's a great pass-rusher

Starting tackle Sean Lissemore left the second preseason game with an ankle injury.

Kendall Reyes finished second on the team in sacks, pressures and quarterback hits last year. He's solid and only heading into his third year, so improvement is realistic.

The backups are wounded as much as the starters. Lawrence Guy and Damik Scage didn't play in the second preseason game due to injury while Kwame Geathers was carted off in Week 3 with a knee injury.

Youngsters are getting a chance, but this unit might be in need of a veteran presence

GRADE: C

LB: The linebacking crew last year never got a chance to show itself. This core was ravaged by injuries, but when healthy, as expected this year, there is substantial talent.

Outside backer Melvin Ingram returned from offseason ACL surgery in December and never appeared comfortable. His healthy presence instantly improves a Chargers pass rush.

"He's lost weight. He looks phenomenal," fellow linebacker Jarret Johnson told U-T San Diego. "He's moving better than he's ever played, and he's doing it consistently. He's not taking plays off. He understands the defense. It's easy to work with him when he's on the field. Smart player. He's definitely stepping into that (veteran) role."

Johnson will man the other outside spot in his 12th season.

Dwight Freeney should be back and ready to contribute. He played just four games for the Chargers last year before he tore his thigh muscle. Freeney, 34, doesn't have a ton left in the tank, but as a situational rusher, he can still put opposing quarterbacks on the ground occasionally.

The other reserve pass-rushing linebacker is Jeremiah Attaochu. The rookie was taken in the second round from Georgia Tech and if Johnson's skills diminish late in his career, Attaochu could be ready to make an impact immediately.

Donald Butler was re-signed to a seven-year extension in the offseason. The 25-year-old, who will begin his fourth season, finished with 85 tackles in 13 games last year. He earned the starting gig.

Manti Te'o played the early portion of the 2013 schedule with a lingering foot issue. He missed three games, had offseason surgery, but is shelved once again this preseason with a different foot ailment. He may not be ready for the regular season opener.

"It's not the same foot, it's not the same injury - it's something completely different," said McCoy.

Kavell Conner is expected to replace Te'o with the first-teamers.

GRADE: B

DB: The defensive backs underwent more change than any group for the Bolts.

Flowers and Verrett are impact guys, although Flowers has been dinged up during the summer. He should be fine and should relish the chance to play his former team twice. Flowers is still only 28 and has been to the Pro Bowl. He could single-handedly turn San Diego's biggest weakness into a plus.

Verrett hasn't seen much action at camp thanks to shoulder issues. He is listed behind Shareece Wright on the Chargers' depth chart. When healthy, Verrett should be fine. Height is an issue considering how gigantic NFL receivers are, but Verrett can play against the run, too.

Wright started 13 games in 2013.

Eric Weddle has played in and started all 16 games five of the last six years. He is the unquestioned leader of the Chargers' secondary and made the Pro Bowl two of the last three years. Weddle only managed two interceptions en route to Honolulu last year, but his 88 tackles were a high since 2008.

Marcus Gilchrist is the strong safety and he has some work to do. Second-year safety Jahleel Addae isn't much of an upgrade.

GRADE: B-

SPECIAL TEAMS: Veterans Mike Scifres and Nick Novak return as the Chargers' punter and kicker.

Scifres is one of the game's better punters, but his average of 43.2 yards last year was his lowest since 2006.

Novak became rock-solid in 2013, when he converted 35 of 39 field goals. He enjoyed a stretch of 16 consecutive made field goals late last season.

Allen and Royal handled punt-returning duties last year and are listed atop the depth chart again for 2014. Brown is slated to return kicks, but Woodhead could do the job also.

Undrafted rookie Branden Oliver worked some at both return spots during camp.

GRADE: B-

COACHING: McCoy made the playoffs in his first year as a head coach. He was one of two coaches to turn the trick as rookies to the NFL along with Philly's Chip Kelly.

McCoy's big move this offseason was replacing Whisenhunt and he wasted little time in tabbing Reich. McCoy is the offensive mastermind of this squad and the Chargers offense should be just fine. The defense needs improving, but that's out of his hands, other than motivation and final decision-making.

Pagano may be on a bit of a short leash since someone has to take the blame for this defense under-performing. There's enough talent, so long as it stays on the field and not in an ice bath, to win.

GRADE: B

THE SKINNY: The whole key lies with the defense and health. That's an obvious statement when dealing with NFL prognostications, but the simple reality in San Diego is - when fully healthy, this defense can be solid. If injuries linger, especially on that line, and reinforcements aren't added, it could be a long campaign.

Playing in the AFC West does no favors for the Chargers. The Broncos are clearly better than San Diego, but the Bolts should battle the Kansas City Chiefs for second in the division. A runner-up finish in the division should be enough to make the playoffs.

The problem for the Chargers is, last year, they snuck up on people. Full credit, they won a playoff game, but the schedule is much more difficult in 2014.

The ledger gets brutal at the end with final five games against the Baltimore Ravens, New England Patriots, Broncos, San Francisco 49ers and Kansas City Chiefs. The Ravens and the final two against San Fran and KC are all on the road.

That's heavy sledding, especially for a group that needed a late burst to make the postseason a year ago.