Watkins, 24, proved he could stay healthy while with the Rams in 2017, but his numbers didn't stack up among the game's best receivers. The former No. 4 overall pick, acquired from the Buffalo Bills in August, finished with only 39 catches for 593 yards, though he did manage to score eight touchdowns.
The big, physical receiver (6-1, 211 pounds) specializes in stretching defenses vertically. On the Rams, though, that tool mostly benefited the likes of Robert Woods, Cooper Kupp and Todd Gurley underneath.
Watkins initially entered the NFL with the promise of being one of the game's best receivers. He starred at Clemson, and the Bills gave up future first- and fourth-round picks in order to move up five spots and draft Watkins in 2014.
He showed glimpses of star potential in his first two seasons, totaling 125 catches for 2,029 yards and 15 touchdowns in 29 games, but a broken bone in his foot eventually forced him to miss the first eight games of the 2016 season, prompting the Bills to decline their fifth-year option. Buffalo sent Watkins to the Rams in exchange for cornerback E.J. Gaines and a 2018 second-round pick on Aug. 11.
Watkins previously underwent two surgical procedures on his troublesome left foot and also had hip surgery after the 2014 season.
ESPN Rams reporter Alden Gonzalez contributed to this report.