Updated

(SportsNetwork.com) - Oh, to be in the NFC South in 2014.

If the Baltimore Ravens could jump regions and conferences prior to Week 14's slate of games, they'd head to Miami's Sun Life Stadium on Sunday with a comfortable two-game lead and at least one eye toward finalizing arrangements for a home playoff game in early January.

Instead, the trip to South Florida - given the jumbled competitive reality that is the AFC this year - is far more in the class of full-on business desperation than leisurely holiday comfort.

The Ravens and Dolphins are two of six conference teams with 7-5 records through 12 games, which means their get-together takes on particular urgency as the season's final quarter gets under way.

Baltimore seemed destined for a more stable 8-4 record and a firm hold on playoff destiny heading into the fourth quarter last week, but instead saw a 10-point lead evaporate into a 34-33 loss to San Diego.

It was a second straight prolific performance for an opposing quarterback, with Philip Rivers amassing 383 yards and three touchdown passes just six days after Drew Brees threw for 420 yards and three scores in a game the Ravens ultimately won, 34-27, at New Orleans.

Ravens QB Joe Flacco had two TD passes last week before the late meltdown.

Miami enters the game with just 27 completions of more than 20 yards and just one TD pass of that length, but Baltimore coach John Harbaugh isn't lessening the emphasis on secondary performance.

"We've got to make some plays," he said. "That's really what it boils down to."

The return of starting cornerback Asa Jackson from an injured toe could help. The third-year man last played in Week 5 before being placed on the returnable injured reserve list. He had 16 tackles and a pass deflection in early season action before the hiatus.

The loss of Pro Bowl defensive lineman Haloti Ngata certainly won't help. Ngata was suspended four games by the NFL for violating the league's policy on performance-enhancing substances Thursday.

Ngata said he took Adderall and apologized for the transgression that will keep him out of Baltimore's remaining four games of the regular season.

"I made a mistake, and I own this," said Ngata in a statement Thursday. "I took Adderall and take full responsibility for doing this. I am deeply sorry and broken up over this. I let down my family, my teammates, Ravens fans and myself. My hope is that the Ravens make the playoffs, and I believe they can do this. And, then I can come back and help us win."

Ngata, in his ninth season with the Ravens, is the center of Baltimore's defense as the prominent run stopper in the club's 3-4 scheme. He has 31 tackles with two sacks, two forced fumbles and two interceptions in 12 games this season.

"This is disappointing news for the Ravens," said general manager Ozzie Newsome. "We are disappointed with Haloti, but no more than he is with himself."

The Dolphins defeated the New York Jets on Monday to improve to 7-5, but they've allowed better than 200 rushing yards to two consecutive opponents for the first time in 24 years. Coincidentally, the Ravens' backfield is occupied by Justin Forsett, who leads the NFL with a 5.6-yard average per carry and has gained 400 yards while scoring four times in Baltimore's last three games.

Flacco has four passing TDs and no interceptions in the same three-game stretch, and Baltimore for the season is sixth in the league with an average of 27.3 points per game.

"It's hard to overload the box because they have those threats on the perimeter," Miami coach Joe Philbin said. "I think the key for them has been balance."

Dolphins quarterback Ryan Tannehill completed just 21 of 40 passes in a three- point home loss to the Ravens in 2013, but he's been among the hottest QBs in the league lately - completing at least 70 percent of his throws in five consecutive games. The last two passers with six-game runs of 70 percent or better were named Favre (in 2007) and Manning (Peyton, in 2008 and 2012).

Tannehill was 25-for-35 for 235 yards against the Jets.

"Their offense is a spread-option type of an offense that Tannehill runs very effectively - a lot of weapons," Harbaugh said. "They spread the ball out, they spread the formations out, they run the read option, they run the dive, quarterback keepers, quarterback-follow plays."

Miami, which is tied with Buffalo in the AFC East - two games behind New England - faces the Patriots next week before finishing with Minnesota and a home rematch with the Jets.

The Dolphins last made the playoffs in 2008.

"We've talked to them more about the month of December and the importance of each and every game in December," Philbin said. "This one that we have coming up, Baltimore, both on paper and on film, is as good as team as we've seen."

WHAT TO WATCH FOR

Elvis is in the Backfield

Baltimore pass rusher Elvis Dumervil has 12 1/2 sacks in 2014 and was a chronic thorn in Rivers' side last week, forcing three hurries and hitting the San Diego QB twice. Right tackle Dallas Thomas draws the assignment against him after allowing three pressures, but no sacks, in Monday's defeat of the Jets. Thomas could be aided by Tannehill's ability to throw while moving away from rushers.

Beating the Replacement

Miami's Cortland Finnegan was a no-go at cornerback against New York and is listed as questionable for this week. If he's again unable to play, or less than 100 percent, it tilts a matchup in the favor of Ravens veteran Steve Smith. R.J. Stanford started in Finnegan's place Monday, but he'll be much more challenged by Flacco and Smith than he was by the Jets' tandem of Geno Smith and Eric Decker.

OVERALL ANALYSIS

Though the Dolphins have won five of their last eight games - and only dropped the other three by a combined 10 points - a noticeable theme across 12 games is that they've feasted on lesser foes, and struggled with better ones. The five losses have all come against teams with at least seven wins, while the seven wins include Jacksonville, Oakland and the Jets. Baltimore is good, and matches up well.

"We have a huge game down in Miami," Harbaugh said. "There will a lot on the line and they'll be ready and they're good. We'll have a great opportunity to make a move. It's going to be very competitive (and) down to the wire to make the playoffs, to win the division, and we are in the thick of it."

Sports Network predicted outcome: Ravens 28, Dolphins 27