Josh Allen's new backup is his former backup.

The Buffalo Bills are signing quarterback Mitchell Trubisky, according to multiple reports. They're bringing back the former No. 2 overall pick after he spent 2021 with the Bills. Trubisky, 29, was released by Pittsburgh last month after two seasons with the Steelers, making him free to sign with a team before free agency begins March 13.

Josh Allen and Trubisky have remained friends. Allen attended Trubisky and his wife's gender reveal party during their season as teammates. After Trubisky went to Pittsburgh, he surprised Allen on a golf trip to celebrate Allen's birthday and on that same trip, a photo of Allen holding Trubisky's newborn baby went viral.

Buffalo will hope Trubisky's only action is kissing babies and taking a knee in victory formation in blowouts. Trubisky barely left the sidelines behind the immortal Allen three years ago. He played in six games, completing 6 of 8 passes for 43 yards with an interception as a Bill.

Trubisky played in 12 games, starting seven, in two years in Pittsburgh. He was named the opening day starter over then-rookie Kenny Pickett in 2022 but was benched in Week 4. Trubisky started Weeks 14 and 15 last year for an injured Pickett but lost the job in favor of Mason Rudolph, who the Bills defeated in the wild card round of the AFC playoffs.

His best season was with the Chicago Bears in 2018 when he threw for 3,223 yards and 24 touchdowns with 12 interceptions, and rushed for 421 yards and three TDs. He made the Pro Bowl and led the Bears to an NFC North title.

It was a busy day for the Bills. Buffalo released cornerback Tre'Davious White, safety Jordan Poyer, center Mitch Morse, wide receiver Deonte Harty, cornerback Siran Neal and running back Nyheim Hines. The Bills also re-signed safety Taylor Rapp and guard David Edwards, and signed punt Matt Haack after a two-year hiatus with the team.

Trubisky's signing means Buffalo will move on from quarterback Kyle Allen, who is one of the team's 22 free agents.

This article originally appeared on Rochester Democrat and Chronicle: Bills signing QB Mitchell Trubisky to reunite as Josh Allen's backup