IRVING, Texas -- It's only June, but the Cowboys were missing quite a few players from the first mandatory minicamp practice on Tuesday.

Backup quarterback Kyle Orton missed the session with a hamstring injury, which coach Jason Garrett described as a tweak. Also, inside linebacker Bruce Carter started to practice but couldn't finish because he also tweaked a hamstring.

Cornerback Mike Jenkins made his return to Valley Ranch and did some rehab work on his shoulder, on which he had surgery in the offseason. Jenkins is progressing in the rehab process but is behind several of his teammates who are returning from surgeries.

Also among the missing:

Morris Claiborne (wrist), Felix Jones (shoulder), Gerald Sensabaugh (knee), Dan Connor (shoulder), Alex Albright (shoulder), Kevin Kowalski (foot), Tyrone Crawford (calf), Mackenzy Bernadeau (hip), Danny Coale (foot), Jay Ratliff (foot) and Sean Lissemore (rib).

Most of the players are being held out as a precaution and could play if there was a game Sunday. But others, such as Bernadeau and Coale, wouldn't be ready if there was a game this weekend. Instead, Coale and Bernadeau are trying to get ready for training camp.

Coale got out of a walking boot Tuesday and will still use it from time to time until he's fully healed. Coale wore sneakers Tuesday and played catch with a trainer.

"I'm just two weeks out from surgery," said Coale, who needed a broken toe repaired. "I have to walk a little slowly."

There is some good news regarding Jones, who was seen running routes.

"He's done a really good job in his rehab as well," Garrett said. "He hasn't been involved in much of the football part. He has to stay away from any situation where you're working against another opponent. But throughout the offseason he's been running some routes on air and he's been doing some running on the side and he's been making some progress."

Rookie safety Matt Johnson has missed a bulk of the offseason programs because Eastern Washington is still in school, and rookies can't report to NFL teams until their classes are complete.

Jason Witten missed some Tuesday morning meetings due to jury duty. He did report later.