Injury Updates: Kenley Jansen, Danny Espinosa, Corey Hart

With the news that Alex Rodriguez's recovery from hip surgery could potentially take a turn for the worse, we thought it behooved us to update you on some other injuries from around the league that may play into who gets a spot on the roster at the start of the season.

Here's the latest from around the country, as well as information on two injuries that called for the re-working of contracts this winter:

• Los Angeles Dodgers right-hander Kenley Jansen has struggled with an irregular heartbeat the last two years, and underwent minor surgery in October to try to correct the problem for good. The hard-throwing reliever is now completely recovered from the procedure, according to Bill Plunkett of the Orange County Register, and isn't expected to have any issues with his heart going forward.
• Washington Nationals second baseman Danny Espinosa has elected to play through a torn left rotator cuff rather than undergo surgery that would have cost him the first two months of the season, reports Mark Zuckerman of CSN Washington. Originally diagnosed in September as a bone bruise, Espinosa learned of the tear in early October and immediately began rehab to build up the muscles around his rotator cuff. The switch-hitter began swinging a bat on Jan. 1. If Espinosa's shoulder does become a problem, the Nats have Steve Lombardozzi waiting in the wings.
• Milwaukee Brewers first baseman Corey Hart didn't get the news he wanted when he sought a second opinion on his ailing right knee, so underwent arthroscopic surgery Friday morning to start the recovery process as quickly as possible, reports Tom Haudricourt of the Milwaukee Journal-Sentinel. Hart will be out until at least late May, so Matt Gamel -- who is also recovering from knee surgery -- will take over at first base in the meantime.
• Pirates left-hander Francisco Liriano's mystery non-throwing arm injury was revealed last week as a broken humerus bone. The southpaw allegedly broke his upper arm bone in a bathroom fall just days after making his original agreement with the Bucs, relays MLB.com's Tom Singer from an El Caribe report. Liriano's new agreement stipulates that he will lose salary if the injury forces him to the DL at any point in his two years with the club.
• Red Sox first baseman Mike Napoli's mystery injury was also revealed last week. The righty slugger's tests in Boston revealed avascular necrosis in both of his hips, per Gordon Edes of ESPN Boston, which can be just as nasty as it sounds. The condition essentially means that Napoli's hip bones are slowly dying because of poor circulation. In Napoli's case, the complete breakdown of the bone and joint are unlikely to come while still playing -- especially since it was caught early on -- but he may end up needing a hip replacement or two later in life.