But Roethlisberger isn't healthy. He's trying to gut out an injury that won't really heal until the offseason. As Sam Bradford learned while trying to come back from his high-ankle sprain twice, playing makes the injury worse, not better. On Wednesday, Roethlisberger acknowledged he suffered a setback with the ankle when playing Sunday against the Cleveland Browns.
Even with Roethlisberger gutting it out Sunday, the Steelers should be able to get past a Denver Broncos team that is having a hard time passing the ball. But will playing that game make Roethlisberger worse? Probably.
The Steelers have adjusted their offense to help Roethlisberger by going to more shotgun sets. According to ESPN Stats & Information, he's been in shotgun 80 percent of the snaps since suffering the injury in Week 14. Normally, he's in it 54.8 percent of the time.
The Mendenhall injury forces Roethlisberger to do more. Sure, the Steelers can get some decent running out of Isaac Redman and John Clay, but it's Roethlisberger's job to come up with the first downs and scoring plays.
Credit Roethlisberger with being courageous and for being the ultimate team player by staying on the field with an injury that would sideline most players. But how he plays with that injury will determine how far the Steelers will go in the playoffs.
Here are the 10 things to look at during the wild-card round of the playoffs.
1. Rookie Quarterback Bowl: Although winning a playoff game is harder than most fans realize, remarkably, rookie quarterbacks have managed it lately.
Roethlisberger did it in 2004 taking the Steelers to the AFC Championship Game. Joe Flacco did it in 2008. Mark Sanchez did it in 2009. On Saturday, the Bengals' Andy Dalton or the Texans' T.J. Yates will join that list. The Cincinnati-Houston game marks the first time in NFL history that two rookie quarterbacks will start a playoff game against each other. Although he is at home, Yates will face the bigger challenge.
A third-string quarterback during the season, Yates has shown remarkable poise taking over for the injured Matts -- Schaub and Leinart. Texans head coach Gary Kubiak has praised him for learning quickly and not making the same mistakes twice.
Yates won the first meeting against Dalton by engineering 80- and 83-yard scoring drives in the fourth quarter of a 20-19 win. For Saturday's game, though, Yates will have more on his plate than he did in that game. A left shoulder injury won't keep him from playing, but it's a burden that will affect him during a short week of preparation.
Before the injury, teams were having success against Yates. He was sacked six times and threw two interceptions in losses to Carolina and Indianapolis. Dalton, meanwhile, missed Wednesday's practice because of the flu and even spent time in the hospital. He might be a little weak, but he enters this game in a stronger position than Yates because he has the experience of playing the entire season and doesn't have a serious injury.
2. Coaches facing pressure to win: The Bengals-Texans matchup features two coaches who had sensational seasons. Thanks to Carson Palmer's departure and decisions to get rid of Chad Ochocinco and not re-sign Terrell Owens, Marvin Lewis and the Bengals went young. No one expected them to be 9-7 and a playoff team, but Lewis navigated them to the playoffs with a rookie quarterback, a rookie wide receiver and a young, hungry defense.
Texans coach Gary Kubiak, under the pressure of losing his job if he didn't make the playoffs, revamped the defense with coordinator Wade Phillips and survived the losses of Mario Williams and his top two quarterbacks to give owner Bob McNair his first playoff team.
But making the playoffs is one thing. Winning a playoff game is another, so the pressure is on. Lewis is 0-2 as a playoff coach in nine seasons. A playoff victory would help win fans back.
3. Will this game be like Baylor-Washington? NBC grabbed the Detroit-New Orleans game over a chance to have Tim Tebow in prime time for the sheer entertainment of having an offensive shootout.
Saints quarterback Drew Brees threw for 5,476 yards and 46 touchdowns. Lions QB Matthew Stafford threw for 5,038 yards and 41 touchdowns. Expect a high-scoring game. One stat that assures a high-scoring game is how well the Saints play in the Superdome. The Saints have become the greatest show on Louisiana turf. They averaged 41.1 points and 492.6 yards a game in the Superdome in winning eight home games. Only the 1950 Los Angeles Rams averaged more points, and only the 1982 San Diego "Air Coryell" Chargers averaged more yards at home than the Saints.
4. Cover somebody: Lions coach Jim Schwartz has done a sensational job turning around a team that was 0-16 in 2008. In three years, he's taken the Lions to their first playoff appearance since 1999. Schwartz's biggest challenge is containing Brees and the Saints' passing offense. Because of injuries in the secondary, Schwartz has had to get away from man coverage and use more zone. That's a bad formula playing the Saints.
Brees now destroys Cover 2 schemes. He can send tight end Jimmy Graham into the middle of the field to bust zone coverage. If that's covered, he can hit his receivers in the holes in the zone. If those are covered, he can dump the ball off to Darren Sproles.
Schwartz relies on the talents of his front four to put pressure on quarterbacks, and that might be a problem Saturday night. ESPN Stats & Information came up with some scary numbers. The Lions rush four or fewer defenders 78.9 percent of the time this season, the fourth-highest rate in the league. Against four or fewer rushers this season, Brees completed 74 percent of his passes for 4,032 yards and 34 touchdowns. Schwartz might have to think of some man schemes, or Brees will be "The Man" in beating Cover 2.
5. The Steelers will "man up": In the Broncos' last three losses, Tebow has completed only 41.1 percent of his passes and has had seven turnovers. Broncos VP John Elway wants him to pull the trigger and let it rip. The Steelers won't let him. Both the Bills and Chiefs used man-to-man pass defenses to make it harder for Tebow to complete passes.
With a man in front of a receiver, Tebow is challenged even more to complete a pass. According to ESPN Stats & Information, 31.4 percent of Tebow's throws are overthrown or underthrown balls. Last week, Broncos offensive coordinator Mike McCoy went to more two-receiver sets. Normally, Tebow works out of three-receiver formations. By going to two-receiver sets, the Chiefs had to worry only about matching up against two receivers and a tight end, leaving eight defenders to hang around the line of scrimmage to contain the run. The Steelers can't leave Broncos receivers the freedom to catch short passes by playing off. They need to use more press coverage at the line of scrimmage.
6. Backing into playoffs is a bad omen: There was good reason the Broncos didn't pop champagne or pass out AFC West championship hats after their loss to the Chiefs on Sunday. Even though they won the West, they go into the playoffs on a three-game losing streak.
Since the AFL-NFL merger in 1970, eight teams have reached the playoffs despite a three-game, season-ending losing streak. That includes the Broncos and the Texans this season. From that group, only one team -- the 2009 New Orleans Saints -- went to the Super Bowl. Of the 2001 Raiders, 2000 Vikings, 1999 Lions, 1991 Raiders and 1986 Jets, only the Vikings made it to a conference title game, and they lost to the Giants 41-0.
The Saints won the Super Bowl in 2009 because they had Brees at quarterback and Sean Payton calling plays.
The Texans will try to beat the odds with a rookie quarterback (Yates) playing with a bad left shoulder. The Broncos will try to do it with Tebow, who is completing only 46.5 percent of his passes.
7. Ryan's hope: This will be Falcons QB Matt Ryan's third trip to the playoffs, and he needs a win. He's 0-2 as a playoff quarterback, so losing Sunday to the Giants could give him the tag of not being able to win the big game. Maybe that's unfair, but the pressure is on.
Thanks to the addition of rookie wide receiver Julio Jones, Ryan had his first 4,000-yard season. No one understands the pressure facing Ryan more than Giants quarterback Eli Manning. In 2007, Manning got hot and had a 4-0 run in which he beat Tom Brady in the Super Bowl. But other than that season, his playoff record is 0-3. In those losses, he completed 55.4 percent of his passes for only 147.7 yards a game and had six interceptions. The Super Bowl ring erased Manning's negative label.
8. At least it's not grass: Like most quarterbacks who play in domed stadiums, Ryan watches his numbers go down when he plays outside. In the Georgia Dome, Ryan averages 64.8 percent completion of his passes with 49 touchdowns in 30 games and 217.5 yards a game. But his numbers drop significantly when he plays on grass. There, Ryan completes only 57.1 percent of his passes with 25 touchdowns and 19 interceptions in 18 games. His yards per attempt is 7.55 at home and only 6.59 on grass fields. The good news is that Sunday's game at MetLife Stadium is on the turf, where he's a 62.8 percent thrower with 70 touchdowns and 27 interceptions in 44 games.
9. Getting rid of the ball quickly: The Falcons' offensive line has struggled with pass-blocking, particularly at left tackle, where Sam Baker gave up a sack per game in the games he started. The Giants have a great pass rush, and they don't have to blitz to accomplish that. According to ESPN Stats & Information, the Giants had 34 sacks when rushing four or fewer defenders. Ryan took 22 of his 26 sacks against rushes of four or fewer defenders. With that in mind, Ryan might go more no-huddle to tire out the Giants. He'll also concentrate on quicker throws to limit the times he's hit behind the line of scrimmage.
10. Wrap them up: Bengals coach Marvin Lewis and defensive coordinator Mike Zimmer will stress to defenders the need to wrap up running backs and not let them get away. The Bengals have to stop the league's top one-two running back tandem -- Houston's Arian Foster and Ben Tate. Both are great after contact. As a team, the Texans led the league with 1,133 yards after contact, according to ESPN Stats & Information. The Bengals had the third-lowest number in stopping the run before contract at 2.0 yards per rush, which points to their speed on defense. They allowed 1.9 yards per carry after contact, which is the seventh-worst, showing they aren't wrapping up enough and making the tackles.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.