Nick Piecoro

AZ Central Sports

An MRI on Diamondbacks left-hander Patrick Corbin's left elbow showed a tear in his ulnar collateral ligament, the team announced Sunday, and it appears he could be headed toward season-ending Tommy John surgery.

Even if he doesn't need surgery, Corbin likely won't be pitching anytime soon, a crushing blow for a team with designs on contending in the National League West.

He was the team's best starter in 2013 and was scheduled to take the ball on Opening Day in Australia on Saturday against the Los Angeles Dodgers.

Instead, left-hander Wade Miley will take his place. What Corbin's loss does to the rotation once the season begins in earnest remains to be seen. Corbin left his Cactus League start on Saturday with what the team initially called forearm stiffness. He underwent an MRI that showed "damage" to his UCL, according to a statement released by the team.

Corbin is expected to seek a second opinion sometime this week.

Tommy John surgery typically requires a 12-month recovery, meaning if he has the procedure soon he could be close to ready for the start of the 2015 season.Corbin had a breakout 2013 season, posting a 3.41 ERA in a career-high 208 1/3 innings.

His velocity had jumped up over the past 12 months. He sat in the low-to-mid-90s for most of last season and was again pitching in the mid-90s in recent Cactus League outings.