WATCH: Michael Keaton hosts an ‘SNL’ spoofing Final Four, Scientology

The idea that the stars of the NCAA tournament are “student athletes” is a joke, right? No? Well, the very idea of a hoops star actually studying just got some big laughs. On “Saturday Night Live.” Joke enough for you?

It was on the show’s opening bit, an announcement by Duke Coach Mike Krzyzewski (Taran Killam) that freshman Jahlil Okafor has a biology test on Tuesday and will skip the championship game to bone up in the Buffalo Wild Wings Study Tent.

“If they only came to college to play basketball,” Coach K said, “then we’d look pretty silly.” Audience guffaws followed.

Timely stuff — in contrast to the monologue by host Michael Keaton. It was his first time back on the “SNL” stage since 1992, not that you’d know it from the bit that had Killam and Bobby Moynihan begging him to resurrect his roles as Batman (last seen onscreen in 1992) and Beetlejuice (1988). I think I also caught references to “Johnny Dangerously” and “Mr. Mom,” movies almost as old as that Johnny Cash “SNL” that reran in prime time.

Though it’s been a big year for Keaton in the wake of his “Birdman” comeback (unmentioned this week, but spoofed a month ago) and he’s a great comic voice, he seldom dominated a scene on this “SNL,” apparently content to just be one of the gang. In a funny PSA urging Easter calls to grandmas — shot in the style of a wee-hours phone sex ad — the 63-year-old actor was the token grandfather, bragging about his new shower radio and asking about your long-ago friends from kindergarten.

Another centerpiece scene made fun of CNN’s insistence on using goofy graphics and re-enactments to tell the news, extending the idea to concepts including a puppet recap of the Iranian nuclear talks. Here too, Keaton kept it low-key, silently miming with Aidy Bryant and Kenan Thompson to explain Indiana’s religious freedom law. (This scene also had “SNL’s” first rendition of WMAQ-Channel 5 alum Don Lemon, played by Jay Pharaoh as a scold whose “pull up your pants” demand gets remixed.)

Continuing its rapid response to HBO documentaries (See: last week’s Robert Durst digs), “SNL” re-created a memorable piece of the “Going Clear” documentary, the clip of a Scientology music video that was unabashedly ’90s. The Keaton-free parody version, for the “Church of Neurotrology,” had pop-up updates informing us that this person quit the church, this person was sued and this person is now covered in fruit flies.

Other thoughts:

• Observance of the weekend’s holiday — at least the Christian one — came in the show’s final minutes when Keaton played a simpering dude named Michael Keaton but more reminiscent of Stuart Smalley. Sifting through an Easter basket, he offered explanations for the contents, including a Peep he earlier had coughed up whole and a chocolate bunny for which he had sordid plans. Someone there clearly likes this kind of seasonal gag-o-rama, as it was arranged just like Steve Buscemi’s Christmas ornament unpacking in 2011, complete with the aid of a helpful, off-putting female (Kate McKinnon, feeding chicken to a baby chick). A new tradition!

• Though he sat out some of the show’s successes, Keaton was central to the duds, playing ad agency CEO with a bleeding navel-piercing wound and an inventor showing neighbors his invasive creations.

• But he was used to good effect in a little “She’s All That” parody where the wallflower being transformed by the high school stud (Mike O’Brien) is a dorky old math teacher (Keaton).

• Next week Cookie gets tossed into the mix as “Empire’s” Taraji P. Henson hosts for the first time.