St. Louis Rams left tackle Jason Smith irritated a toe injury and will undergo an MRI, the team announced on Thursday.

Smith missed the final six games of the 2009 with a concussion, and returned to the practice field late last month. Bill Coats of the St. Louis Post-Dispatch reported that towards the end of practice on Tuesday, Smith "hobbled heavily" toward the sideline.

After Tuesday's practice, Rams head coach Steve Spagnuolo said that Smith "tweaked" a toe, and that the injury was not considered serious.

After trading Alex Barron to the Dallas Cowboys, the Rams are counting on Smith to man the left tackle position, and to protect 2010 first overall pick Sam Bradford's blind-side.

The Rams used their second-round pick, the 33rd overall choice, on offensive tackle Rodger Saffold, who is expected to play right tackle.