Michael O'Keefe, Spencer Grammer

The HankMed team is going to be pretty busy this summer on Royal Pains.

The USA medical dramedy has added Oscar nominee Michael O'Keefe (Michael Clayton), Shameless vet Nick Gehlfuss, Greek grad Spencer Grammer, Reaper's Tyler Labine, Betas actor Leonardo Nam and Entourage alum Brandon Quinn as guest stars for Season 6, TVGuide.com has learned exclusively.

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First off, Gehlfuss will appear in Tuesday's Season 6 premiere (9/8c, USA) as Lance, a gifted local musician with a possible family disease that could keep his career from taking off. Grammer will play an aspiring NASCAR driver who is distracted from an important race by the health issues of her father and NASCAR crew chief (O'Keefe).

Quinn will (at least try to) romance Divya (Reshma Shetty) as Randy, a cheeky local firefighter who is as persistent as he is smitten in the July 1 episode. Labine will heat things up as Franklin, a talented chef opening a new restaurant in the July 15 episode.

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Nam will portray a young-at-heart house sitter known for his legendary Hamptons house parties until a freak accident turns his hard-partying lifestyle upside down in the July 22 episode.

O'Keefe most recently starred on TNT's King & Maxwell. Gehlfuss also recurred on The Newsroom. Grammer most recently appeared on the short-lived Ironside remake. Labine currently stars on Hulu's Deadbeat. The group joins recently announced guest stars Donna Murphy, Diane Farr and Alpha House alum Willa Fitzgerald.

The new season of Royal Pains premieres Tuesday at 9/8c on USA. Watch the Season 5 finale here.