Rex Ryan’s first problem with the Buffalo Bills is a familiar one, since the lack of a reliable quarterback was his death knell with the New York Jets.

As Ryan takes the podium in Orchard Park, N.Y., Wednesday to be called upon to lead the Bills to the playoffs for the first time in two decades, he will be staring at a doubting media pool and looking into cameras projecting his trademark machismo to hopeful Bills fans.

New offensive coordinator Greg Roman, who has a history with Ryan dating to their time on the Baltimore Ravens’ coaching staff, does not have the luxury of inheriting a top-tier offense. While Ryan gets the keys to the NFL’s fourth-ranked defense, which led the league in sacks, Roman walks into a complete rebuild.

Other than wide receiver Sammy Watkins, that cupboard is bare in Buffalo.

The uncertainty starts under center, where 2014 starting quarterback Kyle Orton retired and former first-round pick EJ Manuel’s short bio includes sitting behind an inglorious array of talent that includes the likes of Thad Lewis and Orton, who was beckoned from a predictably abbreviated retirement to start ahead of Manuel.

Roman’s top priority in San Francisco was developing quarterback Colin Kaepernick, who can throw passes through brick walls and outrun defensive backs but, despite Roman’s best efforts, remains green when it comes to the intricacies of the game.

To diagnose Ryan’s hire alone without knowledge of Roman’s plan — in terms of scheme and personnel — would not be an honest assessment of the move.

In Baltimore, Roman and Ryan were part of a Super Bowl team that was built to run first and second while hoping the defense gave Trent Dilfer enough points not to mess it all up.

With the 49ers, the plan evolved, then seemingly devolved last year, around Kaepernick’s unique set of skills.

Clearly, Ryan believes the identity of a team can be established without the quarterback in a starring role.

Ryan brings something the Bills never established under Doug Marrone, who resigned on New Year’s Eve, or Chan Gailey (16-32 with Bills) or Dick Jauron (24-33) or Mike Mularkey (14-18). For the first time since Wade Phillips, who succeeded Marv Levy — the coach during the Bills’ glory years of the 1990s — the team will have an unquestioned and clearly defined identity. Ryan, who is fond of guarantees, might as well promise it.

If he wants to avoid the same fate as his predecessors, a rush order on a quarterback would be wise.

The Ryan name continues to stand for defense, for nasty and smashmouth football, blitz packages and bruising the other quarterback.

In that light, Ryan is the ideal man for the job in Buffalo. Stacked against the Atlanta Falcons, who also interviewed Ryan, the Bills offer Ryan the personnel to have a top-ranked defense from the opening snap of 2015. Talks with the 49ers likely dissolved for the same reasons, what with Ryan equipped to get firsthand intel from Roman on the crumbling structure that led to Jim Harbaugh leaving for Michigan.

The Bills had three players with at least 10 sacks last season. Defensive end Jerry Hughes might leave in free agency and the contract of defensive end Mario Williams might need to be addressed, but Ryan has more than the foundation of a championship-caliber defense. He took a lesser model to back-to-back AFC Championship games with the Jets, where his defense finished in the top 10 during five of his six seasons — and 11th in 2013.

What the Bills do on the opening snap at quarterback is the bigger worry — the same trap door Ryan never escaped with the Jets.

The open market will not offer an instant upgrade over Orton and there is no obvious road to Camelot through the draft.

Bills fans might yawn and Jets apologists will chuckle at the notion, but Eagles quarterback Mark Sanchez might be the best available hired gun for Buffalo. He became a turnover machine with marginal talent around him with the Jets, cast as more of a rower than the engine of Ryan’s “ground and pound” scheme.

Sanchez, who lost a preseason battle at quarterback with Geno Smith in 2013 before a season-ending injury, did some good things in replacing Nick Foles in 2014. How much of that was Chip Kelly’s innovative design and how much credit goes to Sanchez is known only inside Eagles’ headquarters.

Kelly didn’t solve Sanchez’s turnover issues — he had 14 — but he had only one more than Orton (13).

Because of his magic touch on defense, Ryan does not need Tom Brady or Aaron Rodgers in order to succeed in the AFC East. He might even be able to do it with Sanchez or a lesser QB.

His defense almost always shows well against the alpha male in the division, New England, and there is more individual talent on offense than Ryan had when he first landed with the Jets.

When he was hired by the Jets, Ryan boldly announced he was not in New York to kiss Bill Belichick’s rings.

By relocating to Buffalo, Ryan lands on his feet with a team capable of pricking the balloon of the Jets (Buffalo won both meetings in 2014, by a combined total of 55 points) and bellying up to Belichick’s Patriots bully.

Given his track record, the run of 6-10s and 7-9s and 9-7s that led the Bills to this hire might have turned out differently with Ryan at the helm and Ryan Fitzpatrick, Trent Edwards, Kevin Kolb, J.P. Losman, Kelly Holcomb — or the next journeyman passing through — taking the snaps.

That sales pitch won’t thrill the marketing department or the masses in Western New York.

Ryan’s mission is to prove his first, familiar problem, is not a lasting one. His first move, hiring Roman to run the offense, reflects the pressing nature of finding the right fix.