PITTSBURGH -- Ben Roethlisberger is expected to be the Steelers' starter for the second straight week, though coach Mike Tomlin says his top three quarterbacks will play Sunday night in Denver.
While Tomlin declined Friday to identify which quarterback would open the game, Roethlisberger got extensive work with the starters in practice all week.
After Roethlisberger is pulled, Dennis Dixon will get his first significant playing time with the starters. Dixon has started only one NFL game, and he is expected to be Byron Leftwich's backup when the season starts and Roethlisberger's suspension begins.
Dixon has played and practiced well enough to earn time with the starters, Tomlin said.
"We're looking forward to seeing him take advantage of that," Tomlin said Friday. "There's a great scarcity with first-team snaps in the preseason. We've been very thoughtful and diligent about how we dole those out. We've given deference to the veteran players and Byron Leftwich has taken advantage of his. Dennis has taken advantage of those snaps [he's gotten] and is deserving of his opportunity."
As with most teams, the Steelers will play their regulars longer in the third preseason game than in any other. The starters are expected to get minimal playing time against Carolina on Thursday.
"It [the third game] is the first time you get a legitimate number of first-team snaps," Tomlin said.
Tomlin hasn't said if Roethlisberger will play against Carolina, even though the quarterback cannot play or practice once his suspension begins following that game. Roethlisberger drew a six-game suspension in April for his off-field conduct, but NFL commissioner Roger Goodell is expected to shorten it to four games before the season begins.
First-round draft pick Maurkice Pouncey will start at center and is not expected to split time with Justin Hartwig, the starter the last two seasons. Pouncey got nearly all the work with the first team during practice.
When training camp started, Pouncey was expected to compete with Trai Essex at right guard. Pouncey, who played center at Florida, has impressed Tomlin with his ability to handle all the required blocking calls at the line of scrimmage. Normally, Tomlin said, a rookie cannot handle such assignments.
Starting defensive backs Bryant McFadden (pectoral muscle) and Ryan Clark won't play against the Broncos. Keenan Lewis will start at cornerback for McFadden, while Will Allen will replace Clark at safety.
Clark also sat out last year's regular season game in Denver because playing at a high altitude can trigger a red blood cell condition that caused him to lose his spleen and gall bladder after a 2007 game there.
Matt Stewart, who re-signed last week, will handle all of the long snapping -- a sign that Greg Warren's job is in jeopardy. Stewart was cut before training camp started because the team needed a roster spot for newly signed tackle Flozell Adams.