Leftwich, signed by the Steelers after Charlie Batch broke his collarbone on Aug. 8, is expected to get most of the playing time Thursday when the Steelers face the Carolina Panthers in their fourth and final exhibition game. And it's not only because they want to give Leftwich as many preseason snaps as possible in an offense he began learning only this month.

The Steelers still don't know how quickly Batch can return, though he isn't expected back until the third game of the season at the earliest. That means the Steelers may have a difficult roster decision to make.

They have no plans to cut fifth-round draft choice Dennis Dixon, the former Oregon quarterback who is one of the most versatile skill-position players on the team, and Batch is expected to return in time to avoid going on the injured reserve list, which would end his season.

Carrying four quarterbacks is almost unheard of in the NFL, yet the Steelers very well could begin the season with that many. They probably can't cut Leftwich in anticipation of a swift Batch return because that would leave them only with Dixon in reserve should Roethlisberger get hurt early in the season.

"We will cross that bridge after this performance," coach Mike Tomlin said Tuesday of keeping nearly so many QBs. "I think we have to gather all the information based on the quality of play and the health of Charlie, in terms of what direction we will go. We will hold our cards until necessary."

However, Tomlin offered this about how he plans to split his quarterbacks' playing time Thursday: "We are going to play him (Dixon) and Byron a bunch."

As for Batch's recovery - which the quarterback says is going faster than expected - Tomlin said, "It's too early to tell, to be quite honest with you."

Roethlisberger and the rest of the offensive and defensive starters, including Pro Bowl safety Troy Polamalu, will play about a quarter, but no longer. Polamalu hasn't played in the preseason due to a hamstring injury that occurred before training camp, but wants to get on the field for something other than practice before the Sept. 7 opener against Houston.

"Troy is going to play with the first unit defense," Tomlin said.

Leftwich, the former Jacksonville and Atlanta starter, is 21-of-34 for 170 yards since signing with the Steelers but has yet to throw a touchdown pass, though he did lead the decisive field-goal drive in a 12-10 victory at Minnesota on Saturday. He has been sacked twice.

There's been nothing for the Steelers to dislike about Leftwich, but he didn't take part in any offseason workouts or the first half of training camp with them. That's one reason he played the entire second half against Minnesota and is expected to take the majority of snaps against Carolina.

The Panthers should provide a good test of where Leftwich is, given how they sacked Washington's quarterbacks five times and limited the Redskins to 171 yards passing and 79 yards rushing in a 47-3 victory on Saturday.

"Based on what he has done to this point, there is comfort," Tomlin said. "Every day is so important for him because there have been very few days and opportunities. He has taken advantage of that (time he has gotten) and has been better and gotten better. He needs to continue to do that. Thursday night will be a big part of that."

The Steelers made one roster cut Tuesday, waiving injured tight end Cody Boyd. He spent part of last season with Washington before re-signing with the Steelers.