Cutler injured his groin during defeat to the Washington Redskins in week seven, with his status for the upcoming game with the Detroit Lions still up in the air.
Trestman told NBC Sports: "I don't know where Jay's at really. He's been running around, working out with the trainers. He spent a lot of time on the off day with our director of rehab Bobby Slater, working with bands, redirecting and things like that.
"It'll be day to day and we'll see more on Thursday and Friday. We're hopeful but we've got to be reserved about it as well.
"The doctors are either going to say he can play, and that means he can play without any sense that there's going to be a setback. If he is then he'll go. That's really it. There is no grey area with this."