Callaway, a fourth-round pick in 2018, is currently appealing a 10-game suspension for a second violation of the NFL's substance abuse policy, sources told NFL Network's Ian Rapoport.
The potential ban stems from a tainted CBD product, Rapoport adds.
The 22-year-old was suspended for the first four games of the 2019 season for violating the league's substance abuse policy. He caught eight passes for 89 yards following his reinstatement.
Callaway is a physically talented wideout, but off-field issues have plagued him for most of his football career. He was banned during his final season at Florida before deciding to enter the draft.
Cleveland activated rookie offensive lineman Drew Forbes from injured reserve in a corresponding move.