Even if it is just rumor, it's a pretty good idea. For nearly two decades, New York Yankees' closer Mariano Rivera has been using Metallica's 'Enter Sandman' as his entrance song in the ninth inning. As he prepares to retire this year, some think the band could return the favor by showing up for his retirement ceremony at Yankee Stadium.

The band will already be in town: The New York Daily News' Peter Botte notes that Metallica will be performing at the Apollo Theater on Sept. 21, one day before Yankee fans say their official goodbye. And the group has nothing on its calendar for that date. There's mutual admiration between the pitcher and band. Earlier this year, Rivera was presented with a gold record of the song before a game in Cleveland.

Metallica are currently busy promoting their 3D concert movie 'Through the Never'; their Apollo gig is set to relaunch the Mandatory Metallica channel on SiriusXM radio. The show will be broadcast by the station.

The New York Daily News reports that Yankee spokespersons refused comment on events leading up to and surrounding Rivera's ceremony. But Botte has another suggestion, should the group show up: