Easley signed with the Rams prior to the 2016 season after spending the first two years of his career with the New England Patriots.
Easley tore his ACL on two occasions during his collegiate career.
New England selected Easley with the No. 29 overall pick in the first round of the 2014 NFL draft out of Florida, but he played sparingly in his two years with the team.
He appeared to hit his stride with the Rams in 2016, as he set career highs with 35 tackles and 3.5 sacks as part of a rotation that included Aaron Donald and Michael Brockers.
Losing the 25-year-old is a major detriment to L.A.'s defensive line depth, and it further increases the importance of getting Donald to end his holdout.
Assuming Donald returns to his spot alongside Brockers, the Rams will be forced to turn to some unproven commodities behind them.
Among those likely to step into a greater role with Easley on the shelf are Louis Trinca-Pasat, Mike Purcell and rookie sixth-round pick Tanzel Smart.