Lee was injured after catching a 20-yard pass and getting hit low by safety Damontae Kazee, who was then flagged 15 yards for lowering his helmet to initiate contact. Kazee made contact with Lee's left knee, causing it to bend at an awkward angle.
The news is a blow to the Jags, who re-signed Lee this offseason. The upshot for the 26-year-old receiver is that he got paid this year, earning $10 million in 2018, with $7.25 million fully guaranteed for 2019, per NFL Network's Mike Garafolo.
Lee generated 702 yards and three touchdowns on 56 receptions in 14 regular-season games in 2017. After injuries slowed the start to his career, Lee became a solid, reliable target for Blake Bortles last season, with seven tilts earning five or more receptions.
Lee's injury will put more pressure on a good group of young wideouts to perform for a Super Bowl-caliber roster. Second-year receivers Keelan Cole and Dede Westbrook looked poised to take on bigger roles even before Lee was lost for the year. Both should figure in heavily now. Lee's injury should also open more snaps for second-round rookie D.J. Chark who has impressed during training camp.
The Jags like their young depth at receiver, but coach Doug Marrone didn't shut down the possibility of adding a veteran.