Eminem has sparked speculation he will release a new album next year.

'The Real Slim Shady' hitmaker has hinted his eighth record will come out in 2013 by having the date sewn into a piece of official merchandise.

Ahead of this weekend's baseball World Series showdown between the Detroit Tigers and the San Francisco Giants, a post on Eminem's Facebook page read: ''For a limited time only in honor of the big games and the hometown team's return to The D, we are pleased to offer the Eminem Baseball Tribute Hat in both home and away colors.

''Side panel is dedicated to the landmark Eminem solo albums. A portion of the proceeds will go to The Marshall Mathers Foundation. Get them here. (sic)''

The hat features Eminem's logo on the front and at the side is the proclamation 'World Champion' followed by eight years.

The first seven dates: 1996, 1999, 2000, 2002, 2004, 2009 and 2010 were all years in which the rapper released an album.

A final date, 2013, follows underneath, leading fans to conclude he will release new material in the coming months.

The rapper has previously said he has recorded a song with New York rapper Kendrick Lamar and Lady Gaga for his new album.

He said: ''Yeah, I got this crazy record with Gaga and Kendrick for the upcoming LP. Its called 'Street Lights', and its just a real upbeat record.''