By Todd Archer of ESPN.com

OXNARD, Calif. -- The Dallas Cowboys closed Monday's practice with Joseph Randle joining Darren McFadden and Lance Dunbar with an injury.

Randle, who has been the lead running back since training camp opened, has a slight oblique strain and was held out of the rest of practice after going through a small portion of individual drills. He was examined by head athletic trainer Jim Maurer and did not take another turn in practice.

"We're going to go in here and figure out what we've got to do to get it back right so I can get back out here," Randle said as he walked off the practice field.

Undrafted rookie Gus Johnson took the first-team snaps with Randle out. Fullback Tyler Clutts also received some looks at tailback and scored a touchdown against the first-team defense. The only other healthy tailback on the roster is Lache Seastrunk.

Dunbar missed his fifth straight practice with a sprained ankle but went through his most exhaustive rehab session yet. McFadden is on the active/physically unable to perform list with a hamstring strain, but he is scheduled to make his camp debut on Saturday.

With the Cowboys following a deliberate approach with their injured players, Randle could miss the preseason opener Thursday against the San Diego Chargers and might not play even if healthy, given how coach Jason Garrett has worked his starters in the preseason in recent years.

The Cowboys' search to replace DeMarco Murray will have to wait.