Rex begins building Bills staff

It didn’t take Rex Ryan long to take another NFL coaching gig. The fired Jets coach officially took the Buffalo job Monday, so quick he apparently decided having his situation settled was more important than having a quarterback.

The Bills signed Ryan to a fiveyear contract that will pay him $5.5 million annually, and will introduce him Wednesday. It was presumed by many that Ryan’s top choice was the vacant Atlanta job, and pairing Falcons quarterback Matt Ryan and ready-made offense with his own defensive acumen.

Turns out Ryan didn’t want to wait around for Atlanta, which delayed its decision because Falcons owner Arthur Blank’s 99-year-old mother passed away last week. But with a quarterback depth chart of EJ Manuel and Jeff Tuel, no first-round pick, and Tom Brady & Co. still in the same division, it’s a nervy call.

“He was very impressive during the interview process, as were many of the candidates to which we spoke,” Bills owner Terry Pegula said in a statement, “and we feel Rex is the best fit for our team.”

But the Bills f inished 9-7, with Ryan’s new team having swept his old one this season. They have a dominant defensive line — like his former Gang Green squad — and could become even better with Ryan in charge. The Buffalo defense ranked fourth in points allowed, and was best in the league in sacks-per-attempt.

Ryan ran a hybrid 3-4 scheme with the Jets, while Bills defensive coordinator Jim Schwartz runs a 4-3. ESPN reported Ryan wants to retain Schwartz, but according to the Buffalo News, he is unlikely to stay. That could mean longtime Ryan lieutenant Dennis Thurman will take on the defensive coordinator duties.

Ryan reportedly will hire San Francisco 49ers offensive coordinator Greg Roman, with CSNBayArea.com reporting Roman has already agreed to the job and was flying to Buffalo on Monday to sign a contract.

brian.lewis@nypost.com