LAKE FOREST, Ill. -- The Chicago Bears kicked off a simulated regular-season game week Monday in preparation for Friday’s exhibition matchup against the Seattle Seahawks with a few players sitting out of practice due to injuries.

The Bears held out guards Brian de la Puente (MCL sprain) and Eben Britton (hamstring), cornerbacks Isaiah Frey (hamstring) and Kyle Fuller (ankle), right tackle Jordan Mills (foot) and linebacker Lance Briggs (knee bruise).

Bears coach Marc Trestman called Fuller, Mills and Briggs day-to-day. But Mills hasn’t yet played in a preseason outing, and there’s growing concern that his regular-season availability could be in jeopardy.

The team has taken a conservative approach in bringing along Mills, who in January underwent surgery on a fractured metatarsal in his left foot. Mills wasn’t wearing a walking boot on Monday at Halas Hall, but throughout camp the second-year tackle wore one sporadically.

“Day-to-day, that’s it,” Trestman said of Mills. “It’s really day-to-day. I can’t give you anything more than that. We’re hopeful it’s soon [he returns], but that’s all I’ve heard at this point and time and that’s the way we’ve looked at it: just day-to-day.”

Asked if Mills’ regular-season availability could be in jeopardy, Trestman said, “I’m hopeful that it’s not. I’m not trying to get you to insinuate anything. I’m just hopeful it’s not.”

In other Bears injury news, receiver Chris Williams returned to practice for the first time since injuring a hamstring while catching a 73-yard touchdown in the preseason opener. Tight end Dante Rosario also returned to practice after missing the team’s 20-19 win over the Jacksonville Jaguars on Thursday due to calf soreness.