PITTSBURGH - Tommy Maddox could start the Pittsburgh Steelers' first and last regular-season games. What Ben Roethlisberger did in between guarantees they won't leave home during the AFC playoffs as long as they keep winning.

Roethlisberger didn't play a full game for the first time since becoming a starter, but threw two touchdown passes in a 20-7 victory Sunday over Baltimore that left the Steelers on the brink of the best regular season in franchise history.

Roethlisberger was pulled for precautionary reasons with an unspecified rib injury early in the fourth quarter, not long after Terrell Suggs slammed him to turf during a 2-yard touchdown pass to Jerame Tuman.

The injury didn't appear serious - Roethlisberger completed two passes on Pittsburgh's next possession before Maddox took over. Because the Steelers (14-1) won't play another meaningful game for three weeks, it seems unlikely they would risk playing Roethlisberger next Sunday in Buffalo (9-6).

His teammates are certain he will be ready for their first playoff game Jan. 15 or 16.

"Ben is a tough guy," Jerome Bettis said. "I am not worried about the guy. He wanted to keep going - I really think they stopped him from going on. He's a competitor."

What the Steelers find remarkable is they secured home-field advantage before Week 17 during one of the most competitive AFC seasons ever. No rookie quarterback has taken his team to the Super Bowl, yet it wouldn't surprise the Steelers if Roethlisberger - 13-0 as an NFL starter - does exactly that.

"He's just a lot more comfortable," offensive coordinator Ken Whisenhunt said after Roethlisberger went 14-of-19 for 221 yards and one interception. "The timing of his throws is much better, and that only helps the running game."

The Ravens (8-7), their own playoff hopes now all but gone, never did figure out what the Steelers were doing.

"It's tough, it really is," said quarterback Kyle Boller, who drove the Ravens to the Steelers 35 three times without coming away with any points. "It's losing."

Roethlisberger was 3-for-3 as the Steelers needed only five plays to drive 80 yards on an opening possession finished off by his 36-yard touchdown pass to Plaxico Burress, who was coming off a four-game injury layoff.

But Roethlisberger threw only twice during a 14-play, 71-yard drive to open the second half, with Jerome Bettis and Verron Haynes combining for 12 consecutive runs ahead of the rookie's scoring pass to Tuman that made it 17-7. Bettis gained 117 yards in his sixth 100-yard game in six starts for the injured Duce Staley (hamstring).

Suggs was penalized for roughing Roethlisberger but, despite the acrimony that often exists between the two AFC North rivals, there were no incidents the rest of the game. Maybe it's because the Steelers were in such control they didn't want to risk motivating an opponent that seemed worn down and beaten following the 8½-minute drive.

The Ravens talked of taking a playoff-like intensity into the game, but it didn't show up.

"You've got to respond better than that in those circumstances," coach Brian Billick said.

Now, the Steelers' only challenge is to stay sharp before their next game that counts. That's why Cowher may play his regulars longer than normal against Buffalo in a game meaningful only because the Steelers could complete the best regular season in their 72-season history.

"You don't want to go up there and not play well," Cowher said. "We are playing too well to go up there and not win that football game."

Notes:

The Steelers went 8-0 at home for the first time since their 1979 Super Bowl championship season. ... Bettis' first 100-yard game against Baltimore since 1997 moved him past No. 4 Eric Dickerson in NFL career rushing, though the Jets' Curtis Martin is right behind. Bettis has 13,294 yards to Dickerson's 13,259 and Martin's 13,213. Martin began the day 3 yards ahead of Bettis, but was held to 33 yards by New England. ... The Steelers' only other 14-win season was 1978 (14-2). ... The Steelers' No. 1-ranked rushing defense held Jamal Lewis to 26 yards on 14 carries.