Whose Line Is It Anyway? (The CW, 8 p.m.) — Some might know Rob Gronkowski as the oft-injured tight end of the New England Patriots, but true Gronkheads have been following his career since he was a struggling standup comedian, performing open mics at the Cellar. Tonight on Whose Line, he shows off his skills, and Wayne Brady gets to make a “tight end” joke.
24: Live Another Day (Fox, 9 p.m.) — I caught up with this show over the weekend, and it’s been much better than any show that’s been away for years should be. Yvonne Strahovski helps.
Longmire (A&E, 10 p.m.) — Season premiere. This is a good show. But don’t take our word for it.
Louie (FX, 10 p.m.) — The end of the “Elevator” arc, and the beginning of the “Pamela” trilogy.
Mistresses (ABC, 10 p.m.) — Season premiere. Apparently this show was on last year? Hm.
LATE NIGHT GUESTS: Donald Trump on Letterman; Ricky Gervais on Fallon; Bob Newhart and Constance Zimmer on Ferguson; Nick Offerman, Megan Mullally, and Gilbert Gottfried on Meyers; Kellan Lutz and Kate McKinnon on Conan; Robert DeNiro on Stewart; and Thomas Piketty on Colbert.