"The Steelers broke training camp last week with a host of unanswered questions.

Among the most pressing is whether Rashard Mendenhall is ready to provide a spark to a running game that ranked just 23rd in the NFL last season.

And whether he is able to team with Willie Parker and give the Steelers their first legitimate 1-2 punch at running back since Jerome Bettis side-stepped his way into retirement.

"We know what Willie is," offensive coordinator Bruce Arians said last week. "If Rashard proves to be a real (No. 2 back) we'll do it. If he doesn't, then he'll spell (Parker). We'll just see how that goes."

Parker and Mendenhall got all of the work at running back in the first half of Saturday night's 17-13 preseason loss against the Washington Redskins, and both experienced some success.

Parker scored the first touchdown of the game on a 3-yard run and finished with 13 yards on four carries. Mendenhall rushed for 26 yards on five carries at FedEx Field.

With two preseason games remaining and almost three weeks of practice before the start of the regular season, it is too early to tell how prominent of a role Mendenhall will play in the offense.

But he got rave reviews from running backs coach Kirby Wilson for his performance in the Steelers' preseason opener Aug. 13 following a film review of the game.

Parker said he has noticed a significant change in Mendenhall compared to last season when the latter was feeling his way through the NFL landscape before suffering a season-ending shoulder injury in late September.

"He's more comfortable, he's more patient this year," Parker said. "He's got something on his mind this year. I see him in the weight room each and every day so he's ready for the season."

If the Steelers are hopeful that Mendenhall emerges this season, it is not just because they invested a first-round draft pick in 2008 on the former Illinois star. Parker broke down physically last season after averaging 329 carries in 2006-07, and lightening his workload could preserve the two-time Pro Bowl runner this season and beyond.

"History shows that if you get 300 carries for three or four years," Arians said, "your career ends quick.""