Though the Rangers picked up his $9 million option for 2014, Nathan held the right to void the deal due to a stipulation in his contract allowing him to opt out if he finished at least 55 games in 2013, which he did. The Rangers will not have to pay Nathan the $750,000 buyout he would have commanded were the club to turn down his option outright.
A 38-year-old 6-time All-Star, Nathan joined the Rangers prior to the 2012 season, after spending the previous 13 years with the San Francisco Giants and Minnesota Twins, where he emerged as one of the game's elite closers. A 6th round pick by the Giants in 1995, Nathan accrued a remarkable (for a reliever) 18.4 WAR for the Twins from 2004-2009, twice finishing in the top 5 in Cy Young voting and saving a total of 246 games. In the spring of 2010, Nathan underwent Tommy John surgery, causing him to miss the entirety of the season. He returned in 2011, but his performance was underwhelming as he had a 4.84 ERA in 44.2 innings pitched.
Since joining the Rangers, Nathan has returned to form. He had a 2.80 ERA with 78 strikeouts in 64.1 innings in 2012, and he was even better this year, posting a 1.39 ERA and 297 ERA+ with 73 strikeouts, 43 saves, and a 3.2 WAR in 64.2 innings pitched.
Nathan, who leads all current big leaguers with 341 career saves, will headline an impressive crop of free agent relievers this winter. Top-notch bullpen arms such as Grant Balfour, Edward Mujica, and Joaquin Benoit will join Nathan in this year's pitching-heavy market.