According to Joel Sherman of the New York Post, Alex Rodriguez was playing at least part of this season with a torn hip. This is the same hip that A-Rod had surgically repaired before the 2009 season. Sherman states that this will cause Rodriguez to miss part of the 2013 season.
In accordance with this announcement, the Yankees desperately need to sign a player or players who can play shortstop and third base. As of right now, the Yankees may not have a left side of the infield to open the season. Rumors have the Yankees very interested in free agent shortstop Stephen Drew.
The torn hip is different from the one originally operated on in 2009. His left hip will be operated on. Recovery time will be 3-6 months. That would put A-Rod on track to return in June, if everything heals well.