Major blow to Rams' offensive line

The San Francisco 49ers lost quarterback Alex Smith to a shoulder injury in Week 7 when the Carolina Panthers sacked him with pressure around the right side of the offensive line.

The St. Louis Rams could be at a greater risk for a similar outcome after learning that a concussion would sideline right tackle Jason Smith against Carolina in Week 8.

Smith suffered the injury during a collision in practice Thursday.

Renardo Foster, who started two games for Atlanta as a rookie in 2007, gets the start Sunday (although coach Steve Spagnuolo told reporters Adam Goldberg could move from right guard to right tackle, with John Greco taking over at guard.) The change marks the first time this season the Rams have changed up their starting five on the offensive line.

Injuries on the line were a major factor in the Rams' struggles late last season. Smith missed the final six games after suffering a concussion. The Rams have a bye in Week 9.

Foster is 6-foot-7 and 333 pounds. We have seen other offensive linemen, notably Tyler Polumbus in Seattle, outperform expectations when called upon.

The chart shows the Rams' starting line combination this season. Greco has rotated wtih Goldberg at right guard. Depth at tackle has been a concern, however. The team kept fewer offensive linemen than usual on its initial 53-man roster in part because the ninth- and 10th-best linemen in camp weren't strong enough to earn spots on the roster.

The team's eagerness to part with former starting tackle Alex Barron was understandable on one level because Barron wasn't in the team's long-term plans. Depth at the position suffered in the short term, however.

2010 St. Louis Rams OL Combinations