Cutler missed the last five games due to ligament damage and bruising in his right thumb that forced him to leave Chicago's Week 2 loss to the Philadelphia Eagles late in the third quarter.
"At the end of the day, Jay is our starter," Fox said. "Now that he's healed, he's back to being our starter."
Veteran Brian Hoyer did a decent job of replacing Cutler in the lineup, but Hoyer suffered a broken left forearm in the Bears' 26-10 defeat at Lambeau Field last Thursday night. Fox confirmed that Hoyer underwent surgery on the arm Sunday, and league sources tell ESPN NFL Insider Adam Caplan that Hoyer's projected timetable is 6-8 weeks.
Unproven Matt Barkley took over for Hoyer versus Green Bay, but completed just 6-of-15 pass attempts for 81 yards and two interceptions (18.3 passer rating); erasing all doubt that Cutler would get his job back when the medical staff deemed him ready.
Before getting hurt, Cutler committed three turnovers in seven quarters of play.
The guaranteed portion of Cutler's contract ends after 2016. The Bears can open up $13 million worth of salary cap space if they release or trade him in the offseason.