Updated

There are a lot of reasons to go either way when judging the prospects for the San Diego Chargers in 2011.

For the optimists, look at the No. 1 offense in the NFL. And the pessimists, there were four losses to teams with records of .500 or below in 2010. For the happy folks, there's the No. 1 defense in the NFL. And for those with a perpetual snarl, the Chargers delivered a special teams performance best described as tumultuous last season.

Still, put all the enigmas together and there's enough talent left to expect big things for San Diego this year, especially in an AFC West division they'd ruled as kingpins for four straight seasons and five times out of six years prior to missing out on the playoffs with a 9-7 record in 2010.

And this year, they're tweaking the recipe.

Head coach Norv Turner, long a proponent of the workhorse one-back running game, said in training camp that he's leaning toward a scheme to work in both dynamic young running back Ryan Mathews and tough-guy injury option Mike Tolbert.

"I don't know if [Mathews] will be one of the leading rushers because I think the emergence of Tolbert gives us a chance to have a one-two punch," Turner said. "Tolbert gives us a nice changeup. Obviously he's a physical, hard-to- tackle, punishing runner and Ryan has great speed, so it's a good situation.

"That's the mindset now. Certainly Minnesota hasn't done that. Teams with that featured guy are continuing to let the featured guy run. I think if you have guys that are diverse, you can use two."

The two combined for 1,413 yards and 18 touchdowns on the ground last season, while catching 47 throws for 361 yards from perennially elite-level quarterback Philip Rivers, the league���s 2010 leader in passing yardage.

"It's good having two different, dynamic backs," Mathews said. "Being able to have a one-two punch is going to really wear defenses out. When one set of legs is starting to run low, you get a set of fresh legs in there. We can both take it to the house. That's going to be hard on defenses."

The Chargers have scored at least 400 points in seven straight seasons, an NFL record.

"The coaches know how to put players in the right position," Tolbert said. "When they call my number, I'm going to run to the best of my ability. If not, I'm going to root Ryan on, or Frank [Summers] or Jacob [Hester], Antonio [Gates] or whoever it may be.

���Whoever has the ball in their hands, the whole team is going to root for them. Nobody is going to have a selfish attitude, 'give me the ball. Me, me, me!' We don't have that on this team."

Below we take a capsule look at the 2011 edition of the San Diego Chargers, with a personnel evaluation and prognosis included therein:

2010 RECORD: 9-7 (2nd, AFC West)

LAST PLAYOFF APPEARANCE: 2009, lost to N.Y. Jets in AFC Divisional Playoff

COACH (RECORD): Norv Turner (41-23 in four seasons with Chargers, 99-105-1 in 13 seasons overall)

OFFENSIVE COORDINATOR: Clarence Shelmon (fifth season)

DEFENSIVE COORDINATOR: Greg Manusky (first season with Chargers)

OFFENSIVE STAR: Philip Rivers, QB (4710 passing yards, 30 TD, 13 INT)

DEFENSIVE STAR: Shaun Phillips, OLB (55 tackles, 11 sacks, 1 INT)

2010 OFFENSIVE TEAM RANKS: 1st overall (15th rushing, 2nd passing), 2nd scoring (27.6 ppg)

2010 DEFENSIVE TEAM RANKS: 1st overall (4th rushing, 1st passing), 10th scoring (20.1 ppg)

KEY ADDITIONS: ILB Takeo Spikes (from 49ers), SS Bob Sanders (from Colts), WR Vincent Brown (3rd Round, San Diego State), WR Laurent Robinson (from Rams), DE Corey Liuget (1st Round, Illinois), ILB Kevin Bentley (from Texans), OLB Travis LaBoy (from 49ers), CB Marcus Gilchrist (2nd Round, Clemson)

KEY DEPARTURES: ILB Kevin Burnett (to Dolphins), OLB Antwan Applewhite (to 49ers), LS David Binn (released), RB Darren Sproles (to Saints), WR Legedu Naanee (to Panthers), WR Buster Davis (to Bills), TE Kris Wilson (to Ravens), DE Travis Johnson (not tendered), ILB Brandon Siler (to Chiefs), OLB Brandon Lang (released), CB Donald Strickland (to Jets), S Paul Oliver (to Saints), S Tyrone Carter (not tendered), S Pat Watkins (not tendered)

QB: Eighth-year man Rivers led the NFL with 4,710 passing yards and 8.7 yards per attempt in 2010, while his 2,469 passing yards through the first eight games of last season were the most in league history. He finished with a third straight 4,000-yard campaign and is the only quarterback to have a passer rating above 100 in each of the last three seasons. Rivers also had a career- high completion percentage (66.0) on the way to his third Pro Bowl selection in 2010, and he's thrown at least one touchdown pass in a franchise-record 23 consecutive games. Twelfth-year vet Billy Volek is the quintessential NFL backup, having played seven games or fewer in all but one of those seasons, when he started eight times for Tennessee in 2004 and threw 18 touchdown passes against 10 interceptions. He completed one pass for eight yards in three games in 2010. Wisconsin rookie Scott Tolzien is No. 3 on the depth chart.

RB: Mathews was somewhere between standout and disappointment in his rookie season, as the first-round draft choice started nine games and played in 12 while running for 678 yards and catching 22 balls for 145 yards. He scored seven touchdowns, but fumbled five times and lost three. Mathews has shown glimpses of promise during this preseason, averaging 5.7 yards per carry and scoring once while compiling 109 yards in 19 attempts over San Diego's first three games. Tolbert became a fantasy football phenom in his third season out, rushing for 11 touchdowns and gaining 735 yards in 15 games. He caught 25 passes for 216 yards as well, but also fumbled five times and lost three. LSU product Jacob Hester is a 5-11, 235-pound fullback who led the way for Mathews and Tolbert to combine for four 100-yard games. He was another threat out of the backfield, making 22 catches for 145 yards.

WR/TE: Seventh-year man Vincent Jackson was a 10-game holdout over contract issues in 2010 and wound up with just 14 catches for 248 yards and three touchdowns. In the four previous seasons, he'd gone from 27 catches to 41 to 59 to 68, while twice eclipsing the 1,000-yard barrier and peaking at nine touchdowns in 2009. Connecting him with Rivers all season adds a familiar dimension to a longtime prolific offense. Sixth-year vet Malcom Floyd takes on the No. 2 role after a 37-catch season in 2010 in which he finished with 717 yards and six touchdowns. Of course, no Chargers aerial discussion is complete without the mention of tight end Antonio Gates, who was limited to 10 games due to a foot injury but still caught 50 passes for a 15.6-yard average and scored 10 times. A season earlier, the perennial All-Pro was good for 79 catches and a career-best 1,157 receiving yards. Also on hand is veteran wideout Patrick Crayton, the former Dallas Cowboys extra who came to the Chargers to catch 28 passes for 514 yards last year.

OL: Across the front line, center Nick Hardwick comes back for an eighth season after playing all 16 games last year. He had been limited to just three games in 2009 with an ankle injury, but returned to help the Chargers average 395.6 yards per game on offense. Right tackle Jeromey Clary and left guard Kris Dielman combined to start 31 games last season, with the latter named to a fourth straight Pro Bowl. Massive Marcus McNeill begins his sixth season at left tackle, while right guard Louis Vasquez (6-5, 335) started 10 games and missed six with injuries in 2010. Back to provide depth are swing tackle Brandyn Dombrowski, center Scott Mruczkowski and guard Tyronne Green, and the Chargers took Michigan rookie Stephen Schilling in the sixth round of this past year's draft.

DL: Fifth-year nose tackle Antonio Garay made 48 tackles and registered 5 1/2 sacks in 2010, his second season with the Chargers after two with Chicago and one with Cleveland. Rookie end Corey Liuget was the 18th overall selection of April's draft, and the Illinois product will compete for a starting slot with returnee Jacques Cesaire, who made 31 tackles and 1 1/2 sacks a year ago. On the other side is seventh-year man Luis Castillo, who's come up with 19 sacks in six seasons of playing 10 or more games. He started all 16 last year and recorded 26 tackles with 2 1/2 sacks and a fumble recovery. Sliding between end and tackle is Canadian-born Vaughn Martin, a reserve for 20 games over the last two years, in which he's posted 12 tackles and a sack.

LB: Outside linebacker Shaun Phillips was a half-sack off his career high after recording 11 last season to go along with 55 tackles, seven passes defended, an interception return for a touchdown and a fumble recovery. On the clock for time at the other outside slot are 2009 first-round pick Larry English (17 tackles, 3 sacks) and new addition Travis LaBoy (28 tackles, 5 sacks), who's split six seasons between Tennessee, Arizona and San Francisco and registered 28 sacks over that span. Inside, 14-year pro Takeo Spikes comes to San Diego after three seasons in San Francisco, where he went over 100 tackles for the seventh time in his career last year and added a sack, nine passes defended and three interceptions. Returning to compete inside is former third-round pick Donald Butler, who tore his Achilles tendon in last summer's training camp and missed all of his rookie season. Also on hand are rookies Jonas Mouton (2nd Round, Michigan) and Andrew Gachkar (7th Round, Missouri) and five-year vet Antwan Barnes (17 tackles, 4.5 sacks)

DB: Tenth-year cornerback Quentin Jammer made 45 tackles and intercepted two passes as a starter in 2010, when he was flanked by first-year regular Antoine Cason. The two helped the Chargers allow a league-low 177.8 pass yards per game, with Cason finishing with 67 tackles and intercepting four passes with one forced fumble. Hard-hitting safety Bob Sanders signed as a free agent from Indianapolis, where he's played just nine games in the last three seasons after a 3 1/2-sack campaign with 96 tackles and two picks in 2007. At the other safety is Eric Weddle, who defended 10 passes, intercepted a pair and also made 96 tackles last year. Dante Hughes (20 tackles) and rookie Marcus Gilchrist (2nd Round, Clemson) will be the primary nickel backs, with Steve Gregory (42 tackles, 2 INT) and Darrell Stuckey backing up at safety.

SPECIAL TEAMS: Everyone says special teams are important, but in San Diego's 2010 meltdown, they really were. The Chargers allowed three kickoff returns and one punt return for touchdowns and had five punts blocked last year. Consequently, special teams coach Steve Crosby was fired following the season. With standout Darren Sproles exiting via free agency, Crayton and Gilchrist are competing to be the main kick returners, with Gilchrist set to help out reserve receiver Richard Goodman on kicks. Veteran punter Mike Scifres finished second in the AFC with a gross average of 46.7 yards per boot in 2010, while reliable kicker Nate Kaeding drilled 23-of-28 field goal attempts and missed just twice from under 50 yards out.

PROGNOSIS: Just as it's been for the last several years, and in spite of last season's issues, the Chargers enter the 2011 fray as favorites in the AFC West based on their slew of talent across the field and obvious statistical achievements. The schedule begins with three home games in four weeks against Minnesota, Kansas City and Miami, with a visit to New England also on the docket. Three straight road games at Denver, the New York Jets and Kansas City are split up by a bye week before that stretch ends with a home game against Green Bay. Oakland, Chicago, Denver and Jacksonville make up the third quarter of the season and provide a prelude to the homestretch of Buffalo, Baltimore, Detroit and Oakland, with the last two games on the road. A 3-1 performance in each of those segments isn't out of the question for San Diego, which would place the Chargers in position for another postseason home game and potential breakthrough.