BOURBONNAIS, Ill. – Thomas Jones was slated to be a backup in the Chicago Bears’ first training camp practice Thursday. As it turned out, he didn’t take part in any drills because he was injured in rare fashion – while taking his physical.

Jones, who last season joined Walter Payton as the only Bears’ running backs to eclipse 1,300 yards, strained his hamstring while running during the morning physical.

“I may not have stretched as much as I should have been,” Jones said. “It was something that just happened. It could happen to anybody.”

Jones was put on a “physically unable to perform” list to start camp and will be re-evaluated daily, the team said. He was demoted off the first team during a June mini-camp after skipping voluntary offseason workouts and 2005 first-round draft choice Cedric Benson moved up with the No. 1 unit.

One offseason report said Jones, unhappy with his contract and his status relative to Benson, would prefer a trade.

“As far as the trade situation, I really don’t have a comment on that,” Jones said Thursday. “Those are things that aren’t important. I’m here at training camp trying to get ready.”

Jones had 1,335 yards rushing last season and gained 948 yards in 2004, his first year with the Bears. He has two years left on his contract.

“Anybody who has done what I have done the last couple of years I mean is a guy that should be a starter,” Jones said. “I think I was a leader on the offense the last two years. I think I’ve been very productive despite some of the situations that I’ve had to be in. I’ve worked hard. I’ve kept my mouth shut and I stay out of trouble. I do what I’m supposed to do. … So as far as me being the starter, I was the starter the past two years so we’ll see how that goes.”

Jones acknowledged that money sometimes dictates the course of the NFL, and the Bears are paying Benson handsomely to play, not sit. He signed a five-year contract after a 36 day holdout a year ago and received approximately $17 million in guaranteed money.

“It’s not just a football league,” Jones said after being mainly a spectator at Thursday’s practice. “There’s a business side, too. A lot of people don’t understand that. … I just am trying to focus on what I have to do, which is being here, playing football and letting everything else happen the way it happens.”

Coach Lovie Smith said Jones was aware of the rotation with Benson on the first team.

“There weren’t any surprises when he came here,” Smith said.