McBride plays Kenny Powers on the show, a loud-mouthed former Major League Baseball player and single parent.
Steve Little, Katy Mixon, and Elizabeth De Razzo also star on Eastbound & Down. McBride is also co-producer on the show along with comedian Will Ferrell.
Variety reports that HBO has ordered eight more episodes of the comedy, which finished its third season in April.
The cable channel also recently renewed its vampire soap True Blood, as well as Aaron Sorkin's new drama The Newsroom.
Eastbound & Down is expected to return to HBO in the new year.
Watch a promo for Eastbound & Down below: