Washington Redskins coach Mike Shanahan announced on Wednesday that safety Brandon Meriweather sprained his MCL and PCL during practice and will miss 2-to-4 weeks.
Shanahan said Meriweather landed awkwardly on his knee.
Meriweather signed with the Redskins in the offseason after spending the 2011 campaign with the Chicago Bears, appearing in 11 games (four starts) and compiling 32 tackles.
The 28-year-old spent the first four seasons of his career with the New England Patriots, the team that drafted him 24th overall in 2007.
The two-time Pro Bowler has made 44 career starts in 75 games, accruing 293 tackles, two sacks and 12 interceptions.
Shanahan said that DeJon Gomes could get the start Sunday when the Redskins open the regular season against the New Orleans Saints.