Cooper (undisclosed) left Thursday's practice early after making a catch during 11-on-11 drills, Daniel Oyefusi of ESPN.com reports.
When asked about Cooper afterward, coach Kevin Stefanski didn't specify the wideout's injury, noting that the veteran pass catcher is "sore," according to Oyefusi. Given that the team's starters aren't in line to play in Saturday's preseason game against the Vikings, Cooper's next chance to see game action will arrive in Cleveland's exhibition finale against the Seahawks on Saturday, Aug. 24.