Robbins, who disappeared on the eve of the Raiders' Super Bowl loss to Tampa Bay and later sought treatment for mental illness, didn't pass his physical Thursday as the team reported to camp and was subsequently placed on the physically unable to perform (PUP) list.
Robbins underwent arthroscopic surgery on his right knee in May but the injury had not healed sufficiently. Raiders head coach Bill Callahan said Robbins is expected to return to practice Tuesday afternoon.
"I feel like the last three days I've made progress," Robbins said. "I've been able to do some cutting drills and more of the things that will get me on the field."
Since Robbins is not ready for contact, the Raiders will likely ease him back into the mix. Oakland will return to the padded portion of its practices in the afternoon version Tuesday.
"I think that's probably going to be another couple days to a week," Robbins said. "I'm progressing slowly. I think when we do decide to hit -- I will be ready."
Adam Treu remains the starter at center but Robbins being out of action has perhaps allowed Treu to tighten that grip on the position.
"It's really frustrating at this point but I look at the last year for me and how it's been on me, this is really not that tough as far as the big picture," Robbins said. "I'm just looking forward to progressing not just on the field but off the field."
Vince D'Adamo can be reached via e-mail at email@example.com