Mark Duncan, Associated Press
Cleveland Browns quarterback Seneca Wallace (6) passes in the fourth quarter of an NFL football game against the Pittsburgh Steelers, Sunday, Jan. 1, 2012, in Cleveland. The Steelers won 13-9.

CLEVELAND — Rashard Mendenhall leaned on his crutches and bowed his head.

The pain wasn't unbearable for Pittsburgh's leading rusher. However, the thought of missing the AFC playoffs might have been too much to handle.

Mendenhall injured his right knee in the first quarter Sunday and had to watch the Steelers stumble their way to a 13-9 win over the Cleveland Browns, who kept it close but again couldn't come up with the big play to pull off the upset.

Isaac Redman replaced Mendenhall and scored a touchdown, quarterback Ben Roethlisberger made enough big plays on his fragile left ankle and the Steelers (12-4) survived a last-play heave through the falling snow and into the end zone to beat the Browns (4-12) for the 16th time in 17 games.

Pittsburgh didn't get the help it needed to get a first-round bye and will travel to Denver to face Tim Tebow and the Broncos next Sunday.

And the Steelers will likely be without Mendenhall, who went down after a 5-yard gain in the first quarter and didn't return.

"It's not good, of course, when a guy goes down in open grass and is not touched by anyone," Steelers coach Mike Tomlin said. "Experience tells me that in general that's not good."

Tomlin said Mendenhall would have tests after the team got back to Pittsburgh. But the Steelers already seemed resigned to not having Mendenhall for their wild-card game — or maybe at all.

"You should anticipate that he won't be participating next week," Tomlin said.

Mendenhall, who came in needing 110 yards for his third straight 1,000-yard season, was hurt on the final play of the first quarter. He went down without being touched and immediately grabbed his right knee. It was apparent by the reaction of Pittsburgh's offensive players that they knew the injury was serious.

As Mendenhall walked slowly to the sideline, he slapped hands with a few teammates before being examined on a table behind Pittsburgh's bench.

Roethlisberger didn't see Mendenhall get hurt, but said he was upset that some Browns fans cheered his teammate's misfortune.

"I'm really disappointed," said Roethlisberger, who improved to 14-1 in his career against Cleveland. "I know these Browns fans are passionate, but when you hear fans cheer when a guy goes down that's really disappointing. I don't care who it is or if you really hate that team."

Redman scored on a 7-yard run in the third quarter and rushed for 92 yards.

But he fumbled twice in the second half and the Steelers had to hold their breath on the last play when Browns quarterback Seneca Wallace floated a pass into a crowd in the back of the end zone. Pittsburgh safety Troy Polamalu came over the top and got his hand on the ball before Browns rookie wide receiver Greg Little could grab it, allowing the Steelers to escape.

The Browns (4-12) lost their last six games and nine of 10 under first-year coach Pat Shurmur. Cleveland was competitive — the Browns lost their final three games by a combined 13 points — but wound up with one less win than last season and went 0-6 in the division.

"It's not enough wins," Shurmur said. "I want this game to be the last game of the year where we're talking about other things, about where we're playing our playoff game, who we're playing against, those types of things. We've got to win games and I'm obviously not at peace with that.

"Now we'll get to the business of doing what we have to do to get our team as right as we can make it for next season."

Shaun Suisham made two field goals for the Steelers, who won 12 games for the second year in a row, something they haven't done since 1978-79.

Motivated by losing last season's Super Bowl to Green Bay, Pittsburgh opened the season by getting blown out by Baltimore. But the Steelers recovered and will now make another run at a Lombardi Trophy.

"We have a lot of veterans who know what January football is all about," said safety Ryan Clark. "Now's the time to go play it. We kind of limped in and it would have been huge to get a bye and get guys healthy. Now we have to go and play better on the road. I believe this team can win anywhere."

Phil Dawson kicked three field goals for all of Cleveland's points.

Steelers wide receiver Hines Ward had five catches and became the eighth player in NFL history to reach 1,000 career catches.

Ward grabbed a shovel pass in the fourth quarter, and although it lost 3 yards, it got him to the milestone.

"It's the happiest negative-yard catch I've ever had," Ward said. "I always try to put team ahead of personal goals. But 1,000 catches and over 12,000 yards is not bad considering I was a third-round pick."

Notes: Wallace went just 16 of 41 and lost all three starts filling in for McCoy. He said afterward that he wants an opportunity to win the starting job next season. ... Steelers TE Heath Miller had 2 catches, giving him 336 for his career, one more than Hall of Famer Lynn Swann. ... Dawson finished 24 of 29 in his 13th season with Cleveland. "I gave my heart and soul to this team this year," he said. ... Browns RB Peyton Hillis injured his knee while gaining 30 yards on 10 carries. It's unclear if Cleveland will try to sign him as a free agent after a drama-filled season.