The New England Patriots marched their way to the Super Bowl on the right arm of quarterback Tom Brady. But the team's defense, and the secondary in particular, played a momentous role in their success. Cornerback Darrelle Revis wrestled the Best CB in the NFL belt away from Seattle's Richard Sherman while Brandon Browner played tough, physical defense as the team's No. 2 CB. Yet since New England hoisted the Lombardi Trophy, both players have moved on to new teams via free agency, leaving a gaping hole on the Patriots' depth chart.

Who will step up to fill their shoes? Football Outsiders' Aaron Schatz lists Malcolm Butler as a potential candidate, though one not without his flaws.

"How unknown was the hero of Super Bowl XLIX before he got his hands on that final pass to end Seattle's dreams of a repeat?" Schatz wrote. "As of late July, five months after the Immaculate Interception, Butler was still listed on the NFL's website as a strong safety. The three passes Butler got his hand on during Seattle's last drive showed an upside that makes you wonder how he came within a whisker of not even getting an NFL shot. (Playing college ball at Division II West Alabama was part of it.) On the other hand, Butler was just mediocre in his overall regular-season performance and got beat deep a couple time, leading to a 51 percent adjusted success rate (fairly average) and a 10.5 adjusted yards allowed per pass (not good). He'll need more consistency to become a longtime NFL starter and not the Timmy Smith of defensive backs."

Strangely, Patriots head coach Bill Belichick decided not to draft a cornerback until the seventh round in this past NFL draft. That doesn't leave the team with many viable replacements for their departed starting duo. Butler, whether he's ready or not, will be an integral piece of New England's pass defense.