Five problems Bills players have with Rex Ryan's defense

Preston Brown: Coaches sending in play calls too late (2:36)

ESPN Bills reporter Mike Rodak discusses why Preston Brown is the latest member of Buffalo's defense to criticize the coaching staff. (2:36)

When Rex Ryan arrived in Buffalo last January, few expected that one of the NFL's most highly regarded defensive minds wouldn't be able to keep one of the league's top-performing defenses playing at a high level.

Yet despite losing only safety Da'Norris Searcy in free agency and adding one of the NFL's best rookies, cornerback Ronald Darby, in the draft, the Buffalo Bills' defense has largely been in a tailspin since allowing 507 yards in a Week 2 loss to the New England Patriots.

Injuries -- most notably a lingering neck injury to safety Aaron Williams and a season-ending knee injury to defensive tackle Kyle Williams -- have played a role, but the losses in personnel don't fully explain why a unit that allowed fourth-fewest points and yards per game last season has plummeted to 21st in yards allowed and 17th in points allowed.

As the issues have become more glaring, reporters have tried to glean from players what exactly isn't working with Ryan's system and scheme. Here's what has come out of those conversations:

1. It's complicated. Preston Brown, a second-year linebacker who has played in 98 percent of defensive snaps this season, summed up Ryan's scheme Tuesday when he said, "It's so much thinking involved with it. A lot of guys [have] never been a part of [it]. It's definitely been difficult. At times, when [they] let us play, you can see we can be one of the best defenses in the league." Brown wasn't alone in his opinion. Veteran linebacker Manny Lawson said last week that players had a complex playbook to digest this season. "We have to understand that even though Rex is a defensive guru, that’s a lot at one time," he told The Buffalo News. “With these guys here, there is a lot of talent. So a lot of guys here were thrown into situations they weren’t accustomed to and had a big playbook thrown at them."

2. Play calls are coming in too late. This was an issue raised by Brown when speaking to reporters Tuesday. Brown, who has worn the defense's radio helmet since last season to receive play calls, seemed frustrated with some of those calls -- especially adjustments to offensive personnel -- coming in too late from the coaches' booth. "I don't know who that guy is [in the coaches' box], but we talk about it in the meetings," Brown said. "It's been an issue with the personnel coming in and out. I mean, you can see it on games: People are running in and out; we're changing plays here and there. So it's definitely been an issue." He added that even the NFL's slower offenses have noticed and hurried to the line to take advantage of the Bills' confusion.

3. It requires late adjustments to offenses' looks. This was a topic that defensive end Mario Williams broached when speaking to a large group of reporters at his locker following last Sunday's 35-25 loss to the Washington Redskins. "You saw the game, and you're trying to switch personnel as they're coming out of the huddle," Williams said. "I don't know who in the world is calling, saying what personnel they're in or whatever, or how is that confusing. But apparently it is. My mindset is, if you're an attack defense, you don't let anything else dictate what you do. We're gonna put who we're gonna put out there, and then we're gonna execute and make plays with the guys out there. I don't care -- I don't need to wait on you to make a decision." Brown also hit on that theme last week, telling The Buffalo News, “Now we change the whole ... everything. ... It’s a lot more checking this year. It’s a lot more complex. It gets us in the best position possible. We can change the front, the back, whatever we have to do with that formation, we’re going to make sure we’re in the perfect defense for it."

4. Defensive linemen are sometimes required to drop into coverage. This was one of the first signs of trouble, and it came when players spoke in the locker room after the Bills' 34-21 loss to the Cincinnati Bengals in Week 6. "I think I probably set a record on dropping [back] today, but that's part of the scheme for us to go out and be put in a position to win," Mario Williams said. "Whatever's called, you have to go out and do it." Bills defensive linemen, who were used to having the sole job of getting after the quarterback in Jim Schwartz's scheme last season, have had more varied responsibilities under Ryan. "Hey, like [Williams] said, they pay us a lot of money," defensive tackle Marcell Dareus said two days after Williams' comments. "And we want to use our talents the best way we know how. If we're going to be dropping we don't want to get questions about not getting sacks. That's just how it is."

5. The issues haven't gone away. Ryan said after the loss to the Bengals, "We gotta take a long, hard look at what we're asking our guys to do," although less than a week later, he declared, "I looked at it. When you're not successful, you always go back and think, 'Maybe I should have done whatever.' But we will play our defense." Since then, Ryan and defensive coordinator Dennis Thurman have put public pressure on players to execute the plays they call. Williams, however, wasn't satisfied when speaking to reporters earlier this month. "We’re still doing the same thing," he said, according to The Buffalo News.