On Tuesday Pittsburgh Steelers head coach Mike Tomlin confirmed during his press conference that left guard Willie Colon had surgery on his left knee on Monday. The injury is expected to sideline Colon for the rest of the season.

With Colon now sidelined rookie guard David DeCastro will get the opportunity in practice this week to show that he can play. Tomlin said that the plan right now is to let DeCastro play right guard, the position he played at Stanford, and move Ramon Foster over to the left guard spot that Colon manned.

“Our plan is to work David,” Tomlin said, when asked about the offensive line changes on tap. “David\’s worked his way back to health and has been available to us the last several weeks in a backup capacity and participated on PAT\’s and field goal. We believe that his health is at a level now that we can put him in and watch him prepare during the course of the week, and if we like what we see, he may have an opportunity to play. If he does of course we\’ll swing Ramon (Foster) over to left guard, which he has experience at, and he\’s very capable at, and we\’ll leave Maurkice (Pouncey) at center.”

“Obviously, if a guy like (Jay) Ratliff is playing, it would behoove us to have a guy like Maurkice Pouncey at the center position.”

Tomlin was asked if the decision to move Foster over to the left side was made because he has more familiarity with position than DeCastro does.

“Yeah, he has more position flexibility and more comfort in doing so than DeCastro does at this point. So that\’s the chief reason.”

If things go as planned Foster will make his 7th career start at left guard Sunday against the Dallas Cowboys. His last start at the position was last season against the Seattle Seahawks in Week 2.

Foster has been very consistent so far this season on the right side, but hasn\’t been asked to trap block to the left much, as it is not a specialty of his. The Steelers are a right handed running team that likes to run the trap to that side several times during a game, so Foster\’s ability to perform that task this week against the Cowboys will be worth paying attention to.

DeCastro, however, was on the move to the left quite a bit during his time at Stanford at right guard. Could we see the Steelers make a conscious effort this week to run more to the left to take advantage of his strength, assuming he is still as mobile and agile as he was before suffering his right knee injury in the preseason? We shall see.