The running back has not played since sustaining a Lisfranc injury while facing the San Francisco 49ers last September.
The head coach told reporters: "We're really just phasing Santonio in right now. So I have extreme confidence in our medical staff, our training staff. But we're just phasing him in. It's not like he's going out there every snap. We are just phasing him in right now.
"He knows himself better than anybody, but what I've observed, I think he's in great shape, I really do, and I was being truthful when I said that. I'm not trying to hold anything back. I believe that he's in phenomenal shape. I saw him run. He looked pretty good to me. But again, I'm optimistic about it.
"I saw him out there, but to say that he ran a bunch of plays, again, we're just kind of phasing him in. It's not like we repped him with the first team or anything. Right now we're just working him in."
Holmes was taken off the team's physically unable to perform list at the weekend.