Closers aren't supposed to be dominant for extended periods of time, but most closers aren't Mariano Rivera. The Yankees relief ace was still his usual unhittable self this season, until a freak injury during batting practice resulted in a torn ACL and an uncertain future. Rivera's 2012 season was supposed to be his last, but Yankee fans likely expected an extended farewell tour, where the great Rivera would enjoy a slew of richly deserved accolades as he approached retirement. Rivera's season may be over, but will he let his career end like this?
Is Rivera done?
Torn ACLs generally take about a year to rehab, which gives Rivera plenty of time to decide on his baseball future.
Can the Yankees win without Rivera?
Rivera was the Yankees' not-so-secret weapon in the playoffs for many years -- a team looking to beat New York had to beat Rivera first.
The most valuable?
Even the most prolific closer in the majors pitches only a handful of innings per year, but Rivera's influence may have been absolutely outsized in his best seasons.