Andy Samberg and Kit Harington star in HBO’s just-plain-bad “7 Days in Hell.” (Courtesy HBO)

It’s hard to imagine that the pitch session for the regrettably unfunny “7 Days in Hell” (airing Saturday on HBO) actually produced anything more than a polite “no thanks” from the usually discerning network. The bottled water in that meeting must have been gin.

Directed by Jake Szymanski and written by Murray Miller, the film is a feeble attempt at a sports mockumentary, recounting a fictitious 2001 Wimbledon showdown between a mulleted hedonist of a U.S. tennis star, Aaron Williams (“Saturday Night Live” and “Brooklyn Nine Nine’s Andy Samberg), and a stoooopid-but-beautiful British champion, Charles Poole (“Game of Thrones’s” Kit Harington), who keeps getting threatening phone calls from Queen Elizabeth II about what will happen if he doesn’t win this final match.

An array of guest stars serve as interview subjects who provide insight on the historic match, some playing themselves (Serena Williams, Chris Evert, John McEnroe) and others playing characters (Michael Sheen, Fred Armisen, Will Forte, Lena Dunham).

Seeing as how it has only about five minutes of jokes to tell, “7 Days in Hell” might have worked as one of Samberg’s “SNL Digital Shorts” (and even then Lorne Michaels likely would have slotted it in the show’s back end). Instead the film lasts an agonizing 41 minutes a demonstrates a lack of tone, which means you’re never quite sure if you’re watching a comedy that intends to be purely absurd (such as “Zoolander”) or comically realistic (such as “Best in Show”). Even the tennis humor is badly served.