PITTSBURGH — Ben Roethlisberger isn't the only Steelers quarterback who might be out for four weeks.

Byron Leftwich's strained left knee ligament could sideline him for most or all of the first month of the season, leaving the Steelers with only two healthy quarterbacks — Dennis Dixon and Charlie Batch — for their Sept. 12 opener against Atlanta.

Given how secretive coach Mike Tomlin was in refusing to announce a starter for any preseason game, it isn't certain when he'll disclose his starting quarterback. The Steelers don't practice again until Monday.

After the Steelers learned the nature of Leftwich's injury, Dixon was taken out of Thursday's game against Carolina after throwing a single pass, for a touchdown — a strong indication he was being protected for the opener. Batch played the final 2Z\x quarters, throwing only four passes.

After working with four experienced quarterbacks during training camp, an awkward situation that resulted in Batch getting almost no work with the starters, the Steelers suddenly are down to two.

"Of course, I'll be excited if it does come my way," said Dixon, the third-year quarterback who got more preseason playing time with the starters than any quarterback except Roethlisberger. "At the same time, I'm even keel. I never get too high or never get too low."

An MRI exam performed Friday on Leftwich apparently did not reveal a torn anterior cruciate ligament, which could have sidelined him for the season. A strained medial collateral ligament is less serious, but still commonly takes weeks to heal. The team did not disclose any projected timetable Friday.

Now, the Steelers must find a way to remain competitive until Roethlisberger gets back.

"I think we're in good hands," Batch said. "You had three solid guys who could step in when needed, and now we're down to two."