Rams quarterback Sam Bradford has a torn ACL in his left knee for the second straight year and is out for the season.
Coach Jeff Fisher confirmed the extent of the injury Sunday night, news first reported by ESPN and the St. Louis Post-Dispatch.
"We lost our quarterback," Fisher said. "For Sam, it was devastating."
Bradford, the first overall pick of the 2010 draft, missed the last nine games last season after getting injured at Carolina. Veteran Shaun Hill is the backup and the Rams also have rookie Garrett Gilbert and Austin Davis on the roster.
In all, five starters were hurt against the Browns.
Cornerback Trumaine Johnson was carted off with a knee injury and three others - guard Rodger Saffold and defensive tackles Kendall Langford and Michael Brockers - left with ankle injuries.
Johnson will be out 4-6 weeks with an MCL tear, but Fisher said Saffold, Langford and Brockers could play if needed in the preseason finale Thursday at Miami.