If he returns to the field in exactly six months, Machado would be eligible to return on April 15 more than two weeks into the Orioles' 2014 season. The O's primarily used Ryan Flaherty in Machado's absence in the final week of the season, with Danny Valencia and Jonathan Schoop rated the O's No. 4 prospect and top position player by MLB.com other potential options currently on the team's 40-man roster. Machado who started every game from his debut in 2011 until the injury is still projected to play a bulk of the regular season. Named to the All-Star team in his first full season, Machado played Gold Glove-caliber defense at third base and had an American League-leading 51 doubles in 2013. Machado's procedure to repair the torn medial patellofemoral ligament in his left knee went as expected, according to performing surgeon Dr. Neal ElAttrache of the Kerlan-Jobe Clinic in Los Angeles. The 75-minute surgery included an arthroscopy and open reconstruction of the MPFL, and a hamstring tendon was used to graft a replacement for the ruptured ligament. "Manny has some work to do on the rehabilitation part of his recovery, which I'm sure he will do with enthusiasm," Orioles executive vice president Dan Duquette said, according to the Baltimore Sun.