OXNARD, Calif. – Cowboys inside linebacker Zach Thomas, entering his 13th season, hasn't played since November. He played in only five games with Miami last season because of concussion problems.

But when the Cowboys practiced Saturday, Thomas was on the field in full pads, butting heads with guard Leonard Davis, jumping the gap to make tackles and doing all the things he loves.

"Yeah, it was exciting to put the pads on," he said. "This is real football, not flag football. That doesn't count. This is when you find out where the players are."

Family and friends urged Thomas to consider retiring because of health reasons, and they wanted him to retire as a Dolphin. But Thomas dismissed the idea after consulting with doctors, and he felt he could still play.

"That's over-analyzed," Thomas said of the concussion concerns. "I did all my research on that. I don't want to be punch drunk, trust me. I've been hit a few times and I don't want to be that, because I've still got a life after football, and I definitely will turn the page on that when it comes. But time is not up yet. I'm ready to keep going."

■ First-rounders in camp: First-round picks Felix Jones and Mike Jenkins missed the morning practice, and only Jones participated in the afternoon. Jenkins arrived later in the day and did stretching exercises.

Jenkins signed a five-year, $9.725 million contract, with $6.750 million guaranteed, including a $3.1 million signing bonus.

"They called me last night around 12 in the morning and told me it was ready," Jenkins said. "And I had to get all my stuff packed and get out here. It felt pretty good knowing I was on my way up here to be with the rest of the team and compete with everybody else."

Jones signed a five-year, $10.525 million deal with $7.665 million guaranteed, including a $3.57 million signing bonus.

LOUIS DeLUCA / DMN

Zach Thomas, jogging off the practice field following Saturday's afternoon session, joined the Cowboys in the spring after 12 years with the Miami Dolphins.

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Jones was busy in his first practice. He had a few carries in 11-on-11 drills, and was knocked down on a passing play when linebacker Darrell Robertson threw a shoulder into him.

■ Shifts on the line: The Cowboys hope to make their backup offensive linemen more versatile. That's why Pat McQuistan will play right tackle, moving from the left side. Also, James Marten, a tackle, was lined up at left guard in Saturday's practice.

"They're learning more than one position – you have to," offensive line coach Hudson Houck said.

■ Briefly: Owner Jerry Jones said he liked Adam Jones' aggressiveness in the morning practice and said the hardest hit was one the cornerback put on running back Alonzo Coleman. ... Linebacker Darrell Robertson missed a few plays of the morning practice because of a knee injury. He returned for the afternoon practice. ... The Cowboys are expected to sign wide receiver Todd Lowber, if he passes his physical today. He spent time last year on the New York Giants practice squad.