Minnesota Twins closer Joe Nathan will undergo season-ending Tommy John surgery, according to Kelsie Smith of the St. Paul Pioneer Press (via Twitter). Nathan played a game of catch today, and decided afterward that his right elbow required surgery.
Joe Christensen of the Star Tribune writes that Nathan hasn't decided yet where or when he'll have the surgery, but hopes to get it done as soon as possible, aiming to be ready to pitch by Opening Day 2011.
In the meantime, the injury will leave the Twins with a gaping hole in the ninth inning, a spot Nathan had dominated over the past few years. Since joining Minnesota, Nathan has been perhaps the most effective closer in baseball, recording a 1.87 ERA since 2004, with an average of 41 saves per season.
To replace Nathan, the Twins could use an in-house candidate such as Jon Rauch or Matt Guerrier. Or, they could look to make a trade. We've already heard that they might be interested in Heath Bell and Jason Frasor. Now that there's no question that Nathan will miss the 2010 campaign, the team's search for a replacement could become more aggressive.