ALLEN PARK, Mich. (AP) -- Detroit Lions linebacker Kyle Van Noy says it's hard to pinpoint the injury that kept him out of Friday night's preseason win over Jacksonville.
"I can't say where, exactly, because it moves," Van Noy said. "I can't say one specific area."
Van Noy says he's waiting for evaluation of the injury, which the team said was an abdominal problem. The Lions drafted the rookie from Brigham Young in the second round this year.
Van Noy's potential is encouraging to the Lions, but this injury could halt his progress for the time being. He participated in a light drill Saturday during the portion of practice open to reporters, but that doesn't necessarily mean he'll be playing any time soon.
"He still has evaluation to go through and so they'll make a determination on those kinds of things here in the near future," coach Jim Caldwell said. "It was one of those things that progressed and got a little bit worse. It was not one particular event where it happened."
It was unusual for Van Noy to sit out Friday's game.
"That was the first game I've ever missed in my entire life," he said. "It's been pretty frustrating."
With Van Noy out, linebacker Tahir Whitehead impressed Friday. The third-year pro was credited with three sacks.
"He worked at it, he's been performing well," Caldwell said. "He had practiced and played extremely well the last two games and we thought he was deserving of an opportunity because he played like he was one of our top three linebackers and I think from that, he's going to build upon it and I think you're going to continue to see him get better."
Van Noy said he hadn't had an MRI for his injury yet.
"The trainers and doctors may know more," he said. "I don't have the answers."
Detroit put wide receiver TJ Jones on the reserve-physically unable to perform list Saturday. The Lions also released guards Alex Bullard and A.J. Dalton, defensive tackle Greg Hickman, running back Steven Miller, defensive end Kris Redding and wide receiver Conner Vernon.
