The Buffalo Bills have broken the silence on the NFL's head-coaching hiring front, putting the finishing touches Sunday on a deal to make Rex Ryan their next coach, sources told ESPN NFL Insider Adam Schefter.

Ryan is a big name, known for his expertise on defense. He has a big personality. It will be a splashy hire, but is it the right move for the Bills?

It all depends on what Ryan does with their inconsistent offense, which slid to 26th in the NFL in 2014 and spoiled a 9-7 season in which the Bills' defense ranked fourth overall and led the league in sacks. If Ryan wants to turn things around in Buffalo -- and avoid the disaster that ended his tenure with the New York Jets -- he'll need to find the right offensive coordinator and quarterback.

The Bills are pursuing San Francisco 49ers offensive coordinator Greg Roman for the same position, sources told Schefter. Roman was panned this season after the Niners finished 25th in points scored, one factor that kept them out of the playoffs for the first time since 2010.

Whomever Ryan chooses, the Bills better hope it works out better than it did in New York. After trips to the AFC title game in 2009 and 2010, the Jets' offense eventually slid into the gutter. The quarterback situation was a mess. The two primary starters, Mark Sanchez and Geno Smith, threw a combined 93 touchdown passes and 103 interceptions.

Much like the Jets had the past six seasons, the Bills have a quarterback situation that is unsettled at best, and dire at worst. Ryan is making the curious jump from Smith, who helped ruin Ryan's run in New York, to EJ Manuel, who former Bills coach Doug Marrone benched after four games last season in a failed bid to make the playoffs.

If Ryan couldn't get it done with one of the top two quarterbacks from the 2013 draft class, what makes anyone think he could do it with Manuel, the other?

That's why the Ryan hire, while splashy, doesn't mean much for the Bills unless they can find the right quarterback. The pressure is still on general manager Doug Whaley, who backed himself into a corner by trading the team's 2015 first-round pick to move up for receiver Sammy Watkins in the 2014 draft, to find the right signal-caller this offseason.

Whaley should know first-hand how low Ryan's teams can sink without a capable offense. In Whaley's two seasons at the helm, the Bills played the Jets four times and outscored them by a combined 71 points.

Aside from the Jets' home win early in the 2013 season -- a distant memory at this point -- Ryan's last three showings against the Bills were abysmal. The Jets had a combined minus-11 turnover differential, the result of a meltdown at quarterback (whether it was Smith or Michael Vick) and a defense that made Manuel and Kyle Orton look like they would step right over the Jets and into Canton.

That's worth repeating: Ryan, the defensive guru, couldn't stop Kyle Orton, who retired last month before he likely would have been run out of town this offseason. In two games against the Jets this season, Orton had a 139.3 passer rating, six touchdowns and no interceptions. In his 10 other games, Orton's rating dropped to 81.3 and he posted 12 touchdowns and 10 interceptions.

Ryan's once-vaunted Jets defense finished this season 24th in points allowed, 30th in third-down conversion rate allowed and 25th in opposing red zone touchdown rate, which should give pause to anyone who thinks the Bills' defense will automatically remain one of the NFL's best under Ryan's guidance.

Next to Mike Shanahan, Ryan was the biggest name on the coaching market this offseason, and by hiring him, the Pegulas have made their first splash as NFL owners.

Yet it's the Bills' next moves -- what they do at offensive coordinator and quarterback -- that will decide whether picking Ryan was the wise decision.