DeMarco Murray practiced without issue on Monday, which would not be so noteworthy if he had done the same on Sunday. But Murray did not participate in team drills on the first day of Eagles training camp, and the prized free-agent signing did not have an explanation for his conspicuous absence.

Murray, the defending NFL rushing champion with the Dallas Cowboys, said that his lack of participation was a coach's decision. He added that he was not injured.

"You're always upset when you don't get the chance to go out there and compete and take the pressure off the other guys," Murray said. "Obviously, as a competitor I want to be out there, but it didn't happen."

Murray said he did not ask head coach Chip Kelly or running backs coach Duce Staley for an explanation. "I just do what I'm told," he said.

Murray's answers only added mystery to his situation. The running back said there are some days when he takes more practice repetitions than other days. It's not uncommon for a player to manage his practice exertion during training camp - or even for the Eagles' coaches to do so based on body data they gather - but there's not usually an impetus to hold a healthy player back on the first day of camp.

Kelly was not available for comment Monday. He will speak to reporters before practice Tuesday at the NovaCare Complex.

By the time the season begins, a few drills on one day at the beginning of August will not stick out. What will matter is how Murray adjusts to Kelly's offense and how he rebounds from a season in which he carried the ball 392 times, the most of any running back since 2006.

That workload is another reason Murray's activity will be interesting to watch. He said that he's in the best shape of his career and that he understands the importance of his cardiovascular level in the Eagles' offense. He tries to be efficient during practice. He explained that he's in "game mode" during every practice situation and always wants his effort focused on the drill.

"You've got to get good work in instead of just crazy work," Murray said.

The tempo at Eagles practices receives attention, but Murray said the actual time they spend on the field and the workload in practice is comparable to what he has done elsewhere.

"I've always been in good shape and pride myself on being able to run all day," Murray said.

He spent the six-week break between minicamp and training camp getting married, working out, and resting his body. During that time, Hall of Fame running back Emmitt Smith told a Dallas radio station that Murray could have rushed for 2,500 yards last season. It came after Cowboys running back Joseph Randle said Murray "left a lot of meat on the bone" last season. The criticism came even though Murray finished with 1,845 yards last season, the 17th-highest total in NFL history.

"Honestly, I don't know why," said Murray, 27. "I guess it's just part of a deal. There's always going to be critics. I don't look at it as hatred or someone saying anything bad. I really don't pay attention to it, whether it's positive or negative."

Murray's running style - along with his speaking style - differs from his predecessor. He won't be confused with LeSean McCoy, and he admitted he's not a flashy player and does not want to draw any attention to himself.

"Some people might not like that, some guys respect it, but I've always been that guy," Murray said. "Wouldn't change that for anyone."

McCoy carried the ball more than any running back in the NFL during the last two seasons, but Kelly expects the carries to be split among Murray, Ryan Mathews, and Darren Sproles this season. That could help in the Eagles' effort to keep Murray's workload in check after last year's high mileage. Murray does not want that total used against him.

"I moved on," Murray said. "Just make sure I'm mentally, physically, emotionally ready to handle whatever they throw at me. I'm definitely not worried about the amount of touches I get, the amount of touches I had."

During team drills on the first day of practice, though, there were no touches to even log. He was more involved on Monday, and he does not know how the practice reps will be split going forward.

"That's out of my control," Murray said. "It's not up to me. It's up to Duce and Chip. I put a lot of good work in. You always want to be out there as much as you can."