Cleveland's starting right guard Shawn Lauvao will undergo arthroscopic surgery on his ankle and will miss at least the start of the regular season, multiple outlets report.
The injury occurred during a blocking drill in practice.
Lauvao has started every game for the Browns during the last two seasons after playing in 10 games with one start as a rookie in 2010. He was a third-round pick out of Arizona State in 2010.
Browns head coach Rob Chudzinski said Jason Pinkston will replace Lauvao for the time being.
Cleveland was 24th in the NFL last season in rushing yards per game (99.6) and 18th in sacks allowed (36).
The Browns open the regular season Sept. 8 against the Miami Dolphins.