The rapper will play himself, while Aguilera will portray a client and friend of Ari Gold (Jeremy Piven).
Creator Doug Ellin told Entertainment Weekly that Eminem won't be performing in the season ender, but will have a conflict with Vince (Adrian Grenier) — not surprising since the rapper has been known to poke fun at entertainers (Jessica Simpson, Lindsay Lohan, Gov. Sarah Palin, to name a few).
Eminem's latest album Recovery was released June 18; in the HBO series, he'll be in a scene taking place at his album's platinum record party. Ellin says he's confident that Recovery will indeed be platinum by the time the episode airs (Sept. 12).
This isn't the first acting role for Aguilera. The 29-year-old singer has been working on her first film, Burlesque, to be released after her Entourage debut.