Tillman didn't practice Wednesday due to an undisclosed injury, Zac Jackson of The Athletic reports.
Deshaun Watson will get the start in Saturday's preseason opener against the Bears, while Sanders will draw the start in the team's Aug. 22 contest against the Bills.
Watson will start Saturday's preseason game at Chicago, Kelsey Russo of the Browns' official site reports.
The Browns placed Mathis (undisclosed) on injured reserve Tuesday.
The Browns claimed Wright off waivers from the Eagles on Tuesday.
Cook (undisclosed) has been ruled out for Thursday's preseason game against Detroit, Ben Baby of ESPN.com reports.
Hill (hamstring) will not play in Thursday's preseason opener against the Lions, Ben Baby of ESPN.com reports.
Deshaun Watson and Sanders are listed as co-starters on the Brown' unofficial depth chart, Mary Kay Cabot of The Cleveland Plain Dealer reports.
When the Brown' unofficial depth chart is posted later Tuesday, the top QB slot will be listed 'Watson or Shedeur Sanders,' Zac Jackson of The Athletic reports.
Chase and other starters are scheduled to play in Thursday's preseason opener against Detroit, Kelsey Conway of The Cincinnati Enquirer reports.
