Cutler has missed the Bears' last four matches with a high-ankle sprain and McCown has impressed during his time as a replacement, including a fine display in last night's 45-28 win over the Dallas Cowboys, a game in which he threw four touchdown passes and ran for one of his own.
However, Trestman reiterated that Cutler would return to the starting lineup as soon as he is fit enough to play.
"There's no change in the plan. We'll see where Jay is this week. He'll have to be released by the doctors. When Jay is ready to play, he'll be playing," Trestman told reporters.
"When [Cutler] is good to go and can have a full week of practice, he'll be our quarterback."
Cutler is in contention to return in time for Sunday's match against the Cleveland Browns having taken part in limited practice on a couple of occasions last week.