Pirates pitcher Charlie Morton will miss the next 12-to-18 months after undergoing surgery to repair the ulnar collateral ligament in his right elbow.

The procedure, more commonly known as Tommy John surgery, was performed by surgeon Dr. James Andrews.

Morton was placed on the 15-day disabled list on June 1 with inflammation in his right elbow, leading to the diagnosis that resulted in the surgery. He finished the 2012 season with a 2-6 record and a 4.65 earned run average.

In 2011, Morton enjoyed his best season to date, compiling a 10-10 record with a 3.83 ERA while allowing only six home runs in 171 2/3 innings.