St. Louis Rams left tackle Jake Long underwent reconstructive surgery recently on his knee, the St. Louis Post-Dispatch reported Thursday.

Long was injured in the Rams' Week 16 game against the Tampa Bay Buccaneeers on Dec. 22.

Long's right knee buckled while pass-blocking and tests later revealed that he had a torn anterior cruciate ligament (ACL) as well as a torn medial collateral ligament (MCL).

Long, who signed a four-year, $34 million deal with the Rams last March after spending his first five seasons with the Miami Dolphins, waited four weeks so his torn MCL could heal.