So why exactly hasn’t Oklahoma QB Trevor Knight called Katy Perry?

Trevor Knight still hadn’t called Katy Perry, at least as of early Monday afternoon -- more than two days after the pop princess basically pleaded for the Oklahoma quarterback to do so on national television.

Um, why not???

She seems like a lot of fun and also appears to know her college football, having correctly picked several upsets during her extremely entertaining appearance on ESPN’s “College GameDay” on Saturday.

One she got wrong, however, was her choice of Knight’s Sooners over TCU. And the reasoning behind that pick?

“I’m picking this one based on looks. Trevor Knight, do you hear me?” the highly energetic Perry said during the broadcast. “The quarterback for Oklahoma ... I’m going to go with him. Trevor Knight, call me!”

Perry, 29, repeated her request later in the show after pulling out a heart-shaped cutout of the 21-year-old sophomore. “I still love you, Trevor Knight! Call me, call me!”

But ESPN Big 12 reporter Jake Trotter reported Monday that Knight had yet to dial up the superstar. Maybe he was still stewing over those two picks he threw Saturday during a 37-33 loss to the Horned Frogs, despite Perry’s ringing endorsement.

Or maybe it’s because he already has a girlfriend, Kate Williams, a chemical engineering major at Oklahoma.

Trotter suggested that Knight and Perry still had a shot at romance since the “Teenage Dream” singer was scheduled to perform in Tulsa that night. Seems like his plate is pretty full right now though.

Twitter: @chewkiii