OXNARD, Calif. -- The decision to sit out of Friday's afternoon workout was Tony Romo's, according to Dallas Cowboys executive vice president Stephen Jones.

With the Cowboys going through their second workout of training camp, Romo spent the bulk of the workout off the field. He was not in uniform and left the field after the pre-practice warmup was finished. Brandon Weeden took the first-team snaps.

Coach Jason Garrett said the Cowboys want to be mindful of Romo's back injury in back-to-back workouts and standing around can cause issues. The Cowboys will have their first padded practice Saturday, and Romo and club officials said he will take the team snaps during the afternoon session.

"It's just purely precautionary," Jones said. "I think Tony knows that we're getting ready to get into the competitive part of practices [Saturday] and he just decided he wanted to make sure he was rolling and ready and wanted to not push it here. He's been going pretty good between all the conditioning and running and getting himself back into shape. Having a big two or three days here he just wanted to take [Friday] to rest up a little bit and get ready. He doesn't want to miss anything that's competitive and everybody agreed that was a good idea."