It seems that a hit HBO series is getting some new blood for guest stars this upcoming season. E! Online was able to confirm with HBO that Zac Efron will be a guest star on the upcoming sixth season of Entourage.

The site reported that Efron filmed scenes for the show this morning in Beverly Hills at a Niketown store. It wasn't clear what kind of a role he would be playing on the show, but it was said that none of the other Entourage cast members were at the shoot this morning.

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The sixth season will premiere on July 12 and it was also said that other celebrity guest stars appearing as themselves this season include Lil Wayne, Tom Brady, LeBron James and TV producer Aaron Sorkin. Gary Cole, Autumn Reeser and Kate Mara have also joined the cast as new agents and assistants.