Source: Aaron Smith to have MRI

Pittsburgh Steelers defensive end Aaron Smith, who ruptured his triceps Oct. 24 against the Miami Dolphins, will undergo an MRI by Wednesday to help determine whether he will be able to play in Super Bowl XLV, a league source told ESPN NFL Insider Adam Schefter.

Pittsburgh has been saving a roster spot in the hopes that Smith would be able to rejoin the team at some point this postseason. Doctors and the Steelers are hoping that the MRI provides clarity as to whether Smith can play against Green Bay.

Smith has been limited in practice participation the past three weeks.

Smith, a 12-year veteran, doesn't get the notoriety of the better 4-3 pass-rushing ends because he doesn't have the eye-popping sack totals (44 in his career). But in the 3-4 set that the Steelers play, it's the outside linebackers who are relied upon to pressure the quarterback. The defensive ends occupy blockers and clog the line of scrimmage, allowing the inside linebackers to stop the run.

That's where Smith excels. Since his second season as a starter in 2001, the Steelers have ranked among the top three in the league in rushing yards allowed in nine of 10 seasons.

Ziggy Hood, the team's first-round pick in 2009, has made his first nine career starts since Smith was injured. He has four sacks, including one in the postseason, coming in the Steelers' 31-24 divisional-round playoff win over the Ravens.

Information from The Associated Press was used in this report.