PASADENA, Calif. — How might It's Always Sunny in Philadelphia fans feel when they find out that Dennis (Glenn Howerton), rather than going off to be a dad, is teaching (or not teaching) A.P. Bio on NBC?

Maybe they won't have to worry about it.

"First of all, I haven't officially left It's Always Sunny in Philadelphia," Howerton said Tuesday during a session at the Television Critics Association's winter meetings.

Though  Howerton didn't publicly commit Tuesday to returning for the 13th season of Sunny, created by Philadelphia's Rob McElhenney, he did say the schedule of his NBC sitcom would allow him to do both. (Sunny costar Kaitlin Olson already juggles the show with her Fox comedy, The Mick.)

For now, though, he's playing a hot-shot philosopher who, after losing his dream job to a rival, retreats to his hometown and to a job teaching advanced placement biology — a subject he has no intention of actually teaching.

"I think one problem with being on a show for 12 years is that people might have a hard time seeing me as anything else," Howerton said. "That's why it was important to me to do something with someone who has a distinctive voice like Mike [O'Brien, a Saturday Night Live veteran who's producing the show with Seth Meyers and Lorne Michaels]."

He said he hadn't initially planned to jump so quickly into another series, but "I just loved the script."

The series, which costars Patton Oswalt as the school principal, is scheduled to premiere Feb. 1 before returning March 1 after the Winter Olympics.