Ben Roethlisberger in walking boot

HOUSTON -- Wearing a walking boot Sunday when he left the stadium after the Pittsburgh Steelers' 17-10 loss to the Houston Texans, Ben Roethlisberger wouldn't speculate on his availability for next week's game against Tennessee.

Roethlisberger says his left foot was injured on the second-to-last series when he was tackled from behind. He remained in the game but had trouble walking afterward in the locker room.

The Steelers' medical staff initially thought the injury was a sprain and an MRI indicated a possible fracture but was inconclusive because of swelling, team sources told ESPN senior NFL analyst Chris Mortensen.

The team is waiting for some of the swelling to subside Monday morning before initiating more tests, including another MRI.

Roethlisberger had an X-ray after the game, but says he didn't know the results.

"I don't know. I'm still worrying about this game," Roethlisberger said. "It's still too fresh in my mind to worry about next week yet."

Playing with a foot injury wouldn't be new for Roethlisberger. He played part of last season with a broken right foot.

"You know me -- if I can be out there, I'm going to be out there. That's so for next week, too," he said. "If I can do it and if I have to cast it up -- we saw I had to do that last year. I casted up my foot for the last half of the year. If we have to do it, I'll do it."

Roethlisberger was sacked five times Sunday, hit several other times and hurried throughout the day behind an injury-plagued offensive line.

Defensive end Aaron Smith and running back Rashard Mendenhall were also sidelined in Sunday's loss, joining injured linebacker James Harrison.

Smith injured his foot and was carted from the sideline to the locker room. The team revealed after the game he suffered a foot sprain.

Mendenhall scored on a 3-yard run in the third quarter. He didn't appear to be injured on the play, but was replaced by Isaac Redman on the next series.

Harrison left Sunday's game with a right eye injury in the second quarter. He was injured in a collision with a Houston player in the second quarter. He left the field after the play and television shots showed him shaking his head on the bench.

Information from ESPN senior NFL analyst Chris Mortensen and The Associated Press contributed to this report.