He had the same surgery in December 2011, and it is possible that nagging knee pains contributed to the outfielder's struggles this season.
After slugging 23 home runs and 72 RBIs in 123 games in 2011, many were expecting a breakout season for the Missouri native. Instead, Morrison's batting average and home run production fell off in 2012.
Michael Jong of Fish Stripes worries that the six-month recovery from the surgery-- barring any setbacks-- could jeopardize Morrison's readiness for spring training in 2013.
Morrison has been on the disabled list since July 29, and was moved to the 60-day DL on Aug. 16.