The Rams also put new tight end Hunter Long on injured reserve Saturday, one day before their season opener at Seattle.
Kupp injured his hamstring Aug. 1 in training camp, and he aggravated the injury late last month. The Super Bowl 56 MVP got treatment and saw a specialist in Minnesota in recent days but didn't improve enough to play.
Kupp also missed the final eight games of last season with an ankle injury. He won the triple crown of receiving in 2021 and was named the AP's NFL Offensive Player of the Year before leading the Rams to their Super Bowl victory over Cincinnati.
Kupp won't be eligible to play until the Rams host Philadelphia in Week 5 on Oct. 8.
The Rams also signed kicker Brett Maher and quarterback Brett Rypien from their practice squad ahead of their trip to Seattle to face the Seahawks. Rypien will be the backup to Matthew Stafford in the absence of Stetson Bennett, who wasn't put on injured reserve despite a shoulder problem likely to prevent him from suiting up in Seattle.
Los Angeles also signed linebacker Troy Reeder from its practice squad.
AP NFL: https://apnews.com/hub/NFL
The Associated Press