Spikes: Bills' defense will turn heads

ORCHARD PARK, N.Y. -- With several players not fully participating in organized team activities, the Buffalo Bills' defense is hardly a complete unit.

When it returns to full strength, linebacker Brandon Spikes has a message: Watch out.

"I think we're gonna shock the world this year," Spikes said after Monday's practice. "I'm anxious and I think the defense is anxious too. So we're ready to open some eyes."

Spikes joins linebacker Keith Rivers and cornerback Corey Graham as veteran additions to a unit that will also have a new coordinator, Jim Schwartz. However, there are question marks at safety, where the Bills lost Jairus Byrd this offseason, and at defensive tackle, where Marcell Dareus has run into legal and disciplinary issues in recent months.

It's possible that Spikes will help shore up a run defense that ranked 28th last season. It's also possible that the unit will take a step back against the pass. Last season, Mike Pettine's blitz-heavy scheme led to a franchise record in sacks and had some of the NFL's better stats against opposing quarterbacks.

The best way for the Bills' defense to open eyes this season will be if the Bills offense can take a step forward. If the addition of Sammy Watkins and the development of EJ Manuel don't produce more wins, the defense's performances could be for naught, the equivalent of a pitcher losing a 1-0 shutout in baseball.

But if the Bills' defense can hold their opponents to fewer yards, their chances of finishing with a winning record are strong. Over the past five seasons, no team that has finished in the NFL's top five in yards allowed per game has finished with a losing record:

2013: 13-3, 12-4, 11-5, 11-5, 12-4

2012: 8-8, 13-3, 11-4-1, 11-5, 10-6

2011: 12-4, 10-6, 12-4, 13-3, 8-8

2010: 9-7, 12-4, 11-5, 11-5, 10-6

2009: 9-7, 11-5, 9-7, 10-6, 9-7

The Bills finished 10th in yards allowed per game last season. How realistic would it be for them to jump up five spots in that ranking?