CINCINNATI — Four games into the season, oft-injured Chris Perry is the last Cincinnati Bengals running back still standing.

"Kind of ironic," he said today, chuckling. "Hey, I'll try to keep it that way."

The Bengals can't afford to have him hurt. Cincinnati's running game has been a huge disappointment all season, even when Perry's backups were healthy. Kenny Watson hurt a hamstring in practice last Thursday and DeDe Dorsey also suffered a hamstring injury during a 20-12 loss to Cleveland on Sunday, leaving the Bengals' running back collection down to one.

The Bengals signed free agent Cedric Benson to a one-year deal on Tuesday, giving them another running back for their game Sunday in Dallas. He might be needed as more than just a fill-in.

Perry didn't fully participate in practice Wednesday, when the team listed him with a hamstring injury. Perry went through a complete practice Thursday and was surprised to hear the injury report had listed him with a hamstring problem.

"I think it was just giving me time to recover," he said. "I haven't missed a practice since the beginning of training camp. They've got to report something, (so) pick a body part: eenie-meenie-minie-mo. I feel great."

The Bengals want Benson to be able to run some plays against the Cowboys, which would spare Perry from having to play every down. If Perry gets hurt, they would be down to one running back who has been with the team for less than a week.

They're hoping Benson is a quick learner.

"It's going to be tough at first: new scheme, new playbook, things like that," Benson said. "My head is spinning a little bit, but will be a lot more settled by the end of the week."

The Bengals are a hodgepodge heading into their game in Dallas. They don't know whether Carson Palmer will play with a sore passing elbow, or whether the more mobile Ryan Fitzpatrick will make his second straight start at quarterback. And they've got to figure out how to blend Benson into a game plan when he's still learning what to do.

Offensive coordinator Bob Bratkowski said the game plan won't be significantly different.

"You have things that are parts of your offense from Day 1, and you still do a majority of those things," Bratkowski said. "When you select who your backup and third quarterbacks are, you try to have those guys capable of fitting into that system. So really it's not a great departure one way or the other."

Benson was released by the Bears following two offseason arrests in Texas involving alcohol, but the cases were dropped when grand juries chose not to indict last week. The running back had been wondering when he'd get another chance to play in the NFL. When the court cases were dropped, he got his opportunity.

"It's just a humbling experience," he said. "It keeps you grounded. It will bring your feet back to the ground if your feet weren't grounded — the opportunity to look in the mirror, re-evaluate yourself and change yourself for the better."

Having to watch the preseason and the first week of the regular season made an impression on Benson.

"You never wonder if ever, you just want to know when," he said.