LAKE FOREST, Ill. -- The Chicago Bears returned to the field to resume workouts Monday, but continued to hold out defensive tackle Henry Melton and receiver Earl Bennett as the duo works through the steps of the concussion protocol to return to the field.

Melton and Bennett attended the session inside the Walter Payton Center during the portion of practice open to the media, but it appears neither has been cleared to return to activity. Considering the starters aren’t likely to play much, if any, during the preseason finale against Cleveland on Thursday, there’s no rush for Melton and Bennett to return to the field.

“Henry is into (the) running (phase of the concussion protocol). Earl is day-to-day. I know (Bennett) was with some of the medical people this morning, I haven’t checked," Trestman said. "Henry ran today. He’s going to run tomorrow and Wednesday and pick up that running significantly. That’s where he is at this point."

The Bears have already begun preparations for the regular-season opener against the Cincinnati Bengals on Sept. 8, and the week leading into that outing would seem to be the target date for Melton and Bennett to rejoin the team for workouts.

As the club’s franchise player, Melton has already solidified his status as a starter. Bennett, meanwhile, is competing with Joe Anderson, Eric Weems, Terrence Toliver and rookie Marquess Wilson for one of the receiver spots behind Brandon Marshall and Alshon Jeffery. Bennett hasn’t practiced with the team since suffering the concussion on Aug. 3 at Soldier Field after a hard hit from safety Chris Conte.

Melton suffered his concussion in the first game of the preseason at Carolina.

In other injury news, the team held out quarterback Matt Blanchard (hand), linebacker D.J. Williams (calf), offensive tackle Jonathan Scott (knee), defensive tackle (Corvey Irvin) (ankle), cornerback Zack Bowman (hamstring) and linebacker J.T. Thomas (hamstring).

The projected starter at middle linebacker, Williams hasn't yet played in a preseason game, but he's into the running phase of his rehabilitation.

"If you saw him at the (Oakland) game, he was out working at the game," Trestman said. "He's day-to-day, but we'll see where it goes. We're optimistic he's gonna be close (to fully healthy by opening day). It's still day-to-day, but there is progress."

With Williams out of action, rookie second-round pick Jonathan Bostic has filled in at middle linebacker and put together some solid performances throughout the preseason. Still, Trestman wasn't ready to declare Bostic the starter in the middle.

"I am not going to use that term "starting middle linebacker,"" Trestman said. "He has started in the last couple games, and I think he has continued to grow and get better, and (has) shown he can be a very good player in this league. I think he's getting better. He is fitting in. If he happens to be the guy who is that guy Game 1 or Game 2, or whatever it is, I think he can grow into the position and be a more than sufficient middle linebacker in this league."

In other news, fullback Harvey Unga (ribs), defensive end Cheta Ozougwu (hamstring), and long snapper Patrick Mannelly returned to the practice field Monday after missing last week’s game at Oakland.