Former WFAN co-host Chris Carlin is hopping back on the air Wednesday afternoon — alongside Mike Francesa’s biggest competition.

Carlin, who was let go from the “Carlin, Maggie & Bart” show in September, said on Twitter he would be appearing on “The Michael Kay Show” with co-host Peter Rosenberg out for the Jewish holidays.

Kay and his show have been locked in an ugly ratings battle with Francesa, the face of WFAN whose return to the station in 2018 following retirement bumped Carlin’s show to the lesser-appealing 1-3 p.m. slot.

Francesa and Carlin also don’t have the best relationship. Carlin was the producer of Francesa’s old show, “Mike & The Mad Dog,” which was co-hosted by Chris Russo, and when Russo left for Sirius XM in 2008, Francesa believed Carlin sided with Russo through the breakup.

Carlin also sent a profane text message to Francesa and Russo after the pair laughed off WFAN’s sinking ratings during Francesa’s brief retirement.

“Carlin, Maggie & Bart,” which has since been renamed the “Maggie Gray and Bart Scott” show, had strong ratings but parent company Entercom had been mulling axing the three salaries anyway, according to The Post’s Andrew Marchand.