The Steelers aren't taking any chances with their franchise quarterback's sprained right shoulder and dislocated rib.

Though the Steelers confirmed Ben Roethlisberger will return to the starting lineup Sunday against San Diego after missing three weeks with an injury, Roethlisberger will take the field with a little extra protection.

Roethlisberger will play with a custom-fit rib/chest compression shirt and a layer of Kevlar-lined composite in his shoulder pads to help absorb hits to his clavicle and shoulder joint regions.

Whatever he's wearing, the Steelers (7-5) are eager to have him back on the field. Roethlisberger took "90 percent" of the first-team snaps Thursday without any major issues.

"He looks like himself for the most part," offensive coordinator Todd Haley said. "Now I don't know what he's feeling when he's doing some of those things. But it looks like he's moving around pretty good."

Roethlisberger said he felt "good" but declined to expand.

Unhappy reunion

Peyton Hillis lashed back at former teammate Joe Thomas, comparing the Browns' offensive tackle to a "crazy ex-girlfriend" after he made disparaging comments about the Chiefs running back.

Thomas told reporters in Cleveland on Wednesday that Hillis didn't always play hard during his time with the Browns, who play the Chiefs on Sunday. He also accused Hillis of creating a "toxic" environment in the locker room by putting his contract situation ahead of the team.

"Joe Thomas, he can have his opinions all he wants," Hillis said Thursday. "It's kind of like a crazy ex-girlfriend, you know? It's been over a year. Get over it."

Hillis was a breakout star with the Browns in 2011, rushing for 1,177 yards and scoring 11 touchdowns. His hard-nosed playing style made him a fan favorite, and he was even selected to grace the cover of that year's edition of the Madden video game.

He openly campaigned for a long-term contract with the Browns, and, according to Thomas, that proved to be the start of the problems.

"He was everything people knew about him - hardworking, blue-collar, tough, would do anything for anybody on the team," Thomas said. "All he cared about was winning, and then all of a sudden the next year, all he cared about was trying to get his new contract."

Thomas was one of several veterans who encouraged Hillis to clean up his act.

"People who thought they were very close friends with him, he wouldn't listen to anybody," Thomas said.

Sacks record in sight

Aldon Smith hardly has a free moment to stop at his locker, much less give thought to any intriguing matchups or scenarios as he chases Michael Strahan's single-season NFL sacks record.

Yet, come Sunday at Candlestick Park, it won't be the injured Jake Long lining up against the 49ers defensive menace at left tackle for the Miami Dolphins but rather rookie replacement Jonathan Martin.

"I've just got to take advantage of the opportunity," Smith said.

Smith has 171/2 sacks. Next up: getting the 51/2 sacks he needs over the final four games to break Strahan's mark of 221/2 sacks set in 2001 with the Giants.

This article contains information from the Associated Press.