The four teams set to play next weekend enter the playoffs with problems. Patriots quarterback Tom Brady lost his best target, Wes Welker. The Ravens have struggled at wide receiver and in the secondary. The Bengals' already-slow receiving corps must worry about Chad Ochocinco's sore knee, injured during warm-ups before Sunday night's 37-0 loss to the New York Jets. The Jets may be healthy, but they have to try to win two games in six days against the Bengals with a rookie quarterback, Mark Sanchez.
Because next weekend's wild-card games figure to be physical contests in cold locations (Foxborough, Mass., and Cincinnati), the Chargers and Colts have a chance to rest while their divisional-round opponents get banged up.
The pairings for the first round are perfect. The Jets travel to Cincinnati for a 4:30 p.m. ET Saturday matchup of the two lowest-scoring AFC playoff teams. The Ravens-Patriots game, scheduled for 1 p.m. Sunday, features two top quarterbacks -- Brady and Joe Flacco -- who really don't know what they have at wide receiver from week to week. Brady's struggled to find a third receiver and get the ball to tight ends, while Flacco has dependable Derrick Mason and plenty of questions.
Overall, there was a 50 percent turnover in the AFC playoffs from last season, with the Bengals, Patriots and Jets replacing the Steelers, Dolphins and Titans. Philip Rivers and Peyton Manning will sit back for a week and wait to see who stands in the way of their third playoff meeting in three seasons.
Here are 10 questions on the AFC playoffs:
1. What is the key theme for the AFC playoffs?
Quarterbacks. Quarterbacks. Quarterbacks. Five elite quarterbacks dominate the AFC playoffs: Manning, Brady, Rivers, Flacco and Carson Palmer of the Bengals. Having this many elite quarterbacks could make for some great football.
The only one of that group who hasn't won a playoff game is Palmer, who had his left knee blown out in the first quarter of the Bengals' playoff loss to Ben Roethlisberger and the Steelers after the 2005 season. Brady is 14-3 in playoff games, Manning is 7-8, Rivers is 3-3 and Flacco is 2-1. The key matchups could start in the divisional round. Rivers is 0-2 in playoff games against Brady. Manning is 1-2 against Brady but won their last playoff meeting -- the 2006 AFC Championship Game. Rivers is 2-0 against Manning.
2. What are the key injuries heading into the playoffs?
Welker, the Patriots' go-to receiver, appeared to blow out his left knee on a non-contact play less than six minutes into Sunday's 34-27 loss to the Texans. That injury -- believed to be a torn ACL and MCL -- alone could cost New England a trip to the Super Bowl. Take away their easy neutral-site win over the Tampa Bay Buccaneers in London, and the Patriots were 1-6 in road games and faded in the second half. Because they don't throw much to the tight end and don't have a fully developed No. 3 wide receiver, Brady is forced to rely on Welker and Welker alone if Randy Moss slows down in the second half of games. Welker led the NFL with 123 catches for 1,348 yards and four touchdowns. According to ESPN Stats & Information, Brady is a 68 percent passer this year with 8.3 yards per attempt when Welker is in the game. Without him, he completes 58.3 percent of his passes with 5.9 yards per attempt.
Guard Dan Connolly had to be taken to the Pats' locker room Sunday because of an ankle injury. Brady himself is playing with three cracked ribs and a broken right ring finger. The Patriots rested defensive linemen Vince Wilfork (foot) and Ty Warren (ankle) on Sunday, so they should be healthy for the first playoff game.
The Colts have the longest injury list with 12 players, but the bye week should allow defensive ends Dwight Freeney (abdomen) and Robert Mathis (quad), left tackle Charlie Johnson (foot), safety Melvin Bullitt (shoulder) and cornerback Jerraud Powers (knee) to start in their first playoff game.
The Chargers are in good shape because they rested linebacker Shawne Merriman (foot), fullback Jacob Hester (shoulder) and wide receiver Vincent Jackson (Achilles) in Week 17. The only question is safety Eric Weddle, who has a knee injury. Backup defensive lineman Antonio Garay suffered a hamstring injury Sunday.
The Ravens welcomed the return of safety Ed Reed on Sunday. Reed had missed four games with a groin injury. Their only other concern is linebacker Tavares Gooden, who has been out with a groin injury.
Safety Chris Crocker (ankle) was the Bengals' only real concern entering Sunday night, but they suffered some major blows against the Jets. Defensive tackle Pat Sims broke a forearm and is out for the playoffs, affecting an interior line that was already banged up. Safety Tom Nelson injured a knee and his status is uncertain. Ochocinco should be able to play despite a knee injury suffered in pregame warm-ups, but there are concerns about his explosiveness.
The Jets are healthy, other than punter Steve Weatherford, who almost missed Sunday night's game because of a hamstring injury.
3. What styles of games are expected?
Even though three of the league's top four defenses are represented in the AFC playoff field, the potential for high-scoring games exists because of the quarterbacks. The Ravens, Colts, Patriots and Chargers averaged between 24.4 and 28.4 points per game. That could put the Bengals and Jets at a disadvantage because the Bengals score only 19.1 points and the Jets 21.8.
Scoring and big plays have been the ticket to success in the NFL this year. Entering Week 17, according to ESPN Stats & Information, the Patriots ranked second in average yards after the catch. The Colts were seventh, the Chargers ninth, the Ravens 16th and the Bengals 25th. The Pats, for example, average 5.46 yards after each catch, while the Bengals gain only 4.34 yards after receptions. Losing Welker, though, will bring down the Patriots' YAC numbers. Still, that 1-yard gap for the Bengals compared to the better YAC teams could be the difference between first downs and fourth downs. It also may explain why the Bengals score a touchdown per game less than the Colts, Chargers and Patriots.
4. The AFC has become a haven for 3-4 defenses, so how will the 3-4 affect the playoffs?
The Colts and Bengals are the only 4-3 teams; everyone else runs a 3-4. The trend this season has been to pass against 3-4 teams. Look what happened to the Ravens. Last year, they ran the ball 37 times a game to make it easier for Flacco to be a playoff quarterback as a rookie. This year, coach John Harbaugh and offensive coordinator Cam Cameron joined a growing number teams that decided to pass more against 3-4 defenses. The reason is simple: A 3-4 defense with a good nose tackle is hard to run against, so it's easier to spread the field with three or four receivers, try to force the 3-4 into nickel or dime packages, and let the nose tackle stand on the sidelines.
The Chargers aren't as strong against the run without former Pro Bowl nose tackle Jamal Williams, and they are currently down to the their fourth-string nose tackle, Ian Scott. It makes no sense to run at Ravens Pro Bowl nose tackle Haloti Ngata, so it's easier to pass than run against them.
5. Safeties were essential to advancing to the AFC title game last year. What's the story this year?
The trend has shifted to the tight ends, who have a distinct advantage over the safeties in the AFC playoff field. Bob Sanders of the Colts is on injured reserve. Troy Polamalu of the Steelers didn't make the playoffs. Reed missed four games because of a groin injury. That could mean big days for the tight ends.
Pro Bowlers Dallas Clark of the Colts (100 catches) and Antonio Gates of the Chargers (79 catches for 1,157 yards) will create matchup nightmares for defenses. Because of injuries at wide receiver, the Ravens have used tight end Todd Heap in wide receiver splits, hoping he draws a cornerback to create a mismatch. Heap had his best season in years with 53 catches, 593 yards and six touchdowns.
The Bengals and Patriots, however, won't be much of a problem. Only the St. Louis Rams throw to the tight end less than the Patriots. The Bengals' J.P. Foschi and Daniel Coats have combined for only 43 catches.
6. Will running backs be a big factor?
Maybe not. The top three teams aren't much of a threat running the ball. The Colts have two former first-rounders in Joseph Addai and Donald Brown, but both are averaging less than 4 yards a carry. LaDainian Tomlinson has 12 touchdowns and is tough near the goal line, but he's averaging only 3.3 yards a carry.
The Patriots try to run the ball 30 times a game, and defenses have to guess who's going to get the carries. Laurence Maroney lost his starting job in Week 16 when he fumbled at the Jaguars' 1-yard line, his fourth lost fumble of the season. He was inactive in Week 17 even though he was healthy. Kevin Faulk (335 yards) and Sammy Morris (319) have been role players, and Fred Taylor is just getting back from ankle surgery and has only 269 yards.
The Ravens' Ray Rice is the star among the AFC playoff running backs with 1,338 yards and a 5.3-yard average. The Bengals are dependent on big games from Cedric Benson. Rice made the Pro Bowl. Benson was a second alternate.
7. Who has the coaching edge in the AFC playoffs?
The Patriots' Bill Belichick is the most experienced and dangerous playoff coach in the AFC, but he's in a tough spot. New England's road to the Super Bowl has to go through either San Diego or Indianapolis, and it's going to be tough without Welker. Believe it or not, Norv Turner of the Chargers may have the second-biggest edge. He's 3-3 as a playoff coach for the Chargers and has a team that matches up well against the Colts because of its tall pass-catchers and disruptive 3-4 defense. The Ravens' Harbaugh went 2-1 last year in the playoffs, losing to the Steelers in the AFC Championship Game. Jim Caldell is making his first trip to the playoffs running the Colts after taking over for Tony Dungy. The Bengals' Marvin Lewis has had only the loss to the Steelers in 2005. But he's also coached as an assistant in big playoff games in Baltimore.
8. If the game comes down to a big field goal, which kicker would you favor?
Normally, you would say Adam Vinatieri of the Colts, but not this year. Vinatieri hasn't been able to shake a season-long knee injury and it's very likely the Colts will use veteran Matt Stover and not Vinatieri. Vinatieri had only nine field goals this season while Stover made 9 of 11.
Put your money on Nate Kaeding of the Chargers first and Stephen Gostkowski of the Patriots second. Kaeding was 32-of-35 on field goals and kicked many in critical situations. He scored 146 points this year. Gostkowski scored 125 points and was 26-of-31 on field goals.
The Ravens might have been a higher seed had they kept Stover, who wasn't re-signed after the 2008 season. Steven Hauschka was cut after going 9-for-13 on field goals and cost the Ravens two possible victories because of misses. Billy Cundiff was signed off the street and has been solid (12-for-17), but he gave the Ravens a scare by missing two field goals in Sunday's win over the Raiders. The Bengals have a dependable kicker in Shayne Graham, who was 23-of-28 on field goals this season.
9. Can a rookie quarterback be a factor in the playoffs?
It's possible. Sanchez becomes the third rookie quarterback in two years to make the playoffs. The Jets' Rex Ryan becomes the third first-year coach in two seasons to make the playoffs. Ryan came from the Ravens, who made it to the AFC title game last season with a rookie QB (Flacco). Sanchez might have a tougher time. He wasn't as accurate in his rookie year as Flacco or Matt Ryan were a year ago. What will help, though, is that the Bengals aren't a high-scoring team, so as long as Sanchez doesn't throw interceptions, the Jets might have a chance.
10. What are the key rematches in the AFC playoffs?
The Jets play the Bengals only six days after beating them on Sunday night. Having the short week shouldn't be a problem because both teams can use the same game plans. The Patriots beat the Ravens 27-21 in Week 4 in Foxborough, but Brady won't have Welker to help him out this time. The Pats lost to the Colts 35-34 on Nov. 15 in the infamous "fourth-and-2" game. The Colts beat the Ravens 17-15 in Week 11. The Chargers lost to the Ravens 31-26 in Week 2, but they beat the Bengals 27-20 in Week 15.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.