Newman
Coach Wade Phillips said an MRI on Tuesday revealed a "significant" injury to Newman's left groin.
"We're a little disappointed because he plays the nickel for us, he really needs working at it," Phillips said. "We had some specific things we thought we could help him with, so it's going to slow down that process. But he'll just have to study those three weeks."
Newman was on the field in shorts and a T-shirt for the team's only practice Tuesday, like he was for afternoon practice Monday after he got hurt in the morning session that day. Newman was injured when he became tangled up with a receiver during a play and his leg twisted awkwardly.
Newman, the 2003 first-round pick going into his sixth NFL season, has refused to answer questions about his injury.
This is the second year in a row Newman has been injured in the preseason. Last year, Newman was sidelined after the first preseason game because of a slight tear in the tissue in the base of his right foot. He missed the first two games of the regular season.
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Newman still had 62 tackles and four interceptions in 2007.
The latest injury to Newman could mean more time for new cornerback Adam "Pacman" Jones, though Phillips said Jones would for now remain primarily at right cornerback behind starter Anthony Henry on the opposite side of Newman.
"We will move him at some point, but I want to make sure he feels comfortable before we start moving him around," Phillips said. "I think he could certainly do it and he's done it before. I want him to feel comfortable where he is in one place. ... When we get a feel that he's fine there, we'll flip him."
But when the Cowboys started drills Tuesday, Jones was in Newman's spot with the first-team defense instead of rookie Mike Jenkins, one of the team's first-round picks.
While the still-suspended Jones is trying to get back in playing shape after a year out of the NFL, he said this week he was trying to grasp the coverages in the Cowboys' defense.
"He's a football player. He knows how to do a lot of things," Phillips said. "It's getting comfortable with what our terminology is first and then techniques that we want to try to help him do better, and then techniques that are involved in certain coverages that we have."
Returning to the field Tuesday was linebacker Justin Rogers, who sat out Monday due to dehydration sustained when he practiced despite a virus the previous day.
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