Coleman, 24, had 305 yards and two scores on 23 receptions in nine games last season for the Browns. He had 413 yards and three scores on 33 receptions in 10 starts during his rookie campaign in 2016. The Browns selected Coleman with the No. 15 overall pick in the 2016 NFL Draft.
Cleveland traded Coleman to the Buffalo Bills on Aug. 5, before he was waived on Sept. 1.
Fowler, 27, had 350 yards and three scores on 29 receptions in 16 games last season for the Broncos. The 6-foot-1, 212-pound pass catcher has 698 yards and five scores on 56 receptions in 45 appearances during his five-year NFL tenure.
Coleman was signed to a one-year contract. The Patriots made the roster moves after waiving wide receivers Chad Hansen and Riley McCarron. Tom Brady target Julian Edelman is serving a suspension while the Patriots have been playing Phillip Dorsett, Chris Hogan and Cordarrelle Patterson at the position.
Coleman was also scheduled to workout for the Philadelphia Eagles on Tuesday.