SAN DIEGO – On paper, the San Diego Chargers' defensive backfield could be one of the best in the AFC West. But games in the NFL are decided on the field, and San Diego’s secondary has to prove its value in 2015. One player who will be critical to this unit’s success is cat-quick cornerback Jason Verrett. Based on his performance during the first part of his rookie season, Verrett is expected to make a jump in production if he can stay healthy this year.

Locks: Eric Weddle, Brandon Flowers, Verrett, Jimmy Wilson, Jahleel Addae, Darrell Stuckey.

Looking good: Patrick Robinson, Steve Williams, Craig Mager.

On the bubble: Richard Crawford, Greg Ducre, Chris Davis, Lowell Rose, Manuel Asprilla, Gordon Hill, Johnny Lowdermilk, Adrian Phillips.

Chargers free safety Eric Weddle is entering the final season of his contract. AP Photo/Gregory Bull

The good: Although unhappy because of his contract situation, Weddle remains one of the best safeties in the business. At 30 years old, Weddle still has plenty of gas left in the tank. Expect the former University of Utah standout to play with a chip on his shoulder in order to try to impress other teams when he hits free agency at the end of the 2015 season. If they can stay healthy, Flowers and Verrett are one of the better cornerback tandems in the league. Wilson and Addae both bring playmaking ability to the back end of San Diego’s defense, and will compete for the starting strong safety job opposite Weddle. Crawford, Williams and Ducre flashed during offseason work and have a chance to make an impact on the back end of San Diego’s roster if they can contribute on special teams. Robinson and Stuckey are solid pros who provide versatility.

The bad: San Diego had just seven interceptions last season. Only three teams (Jaguars, Chiefs, Jets) finished with fewer. The Chargers have to do a better job of taking the ball away in the back end. None of San Diego’s projected starters and just two defensive backs on the 90-man roster are over 6-feet tall -- 6-1 corner Lowell Rose and 6-1 safety Johnny Lowdermilk. The Chargers could have trouble matching up against big receivers such as Calvin Johnson of the Detroit Lions and A.J. Green of the Cincinnati Bengals in the first two weeks of the regular season. Verrett and Flowers missed a combined 12 games last season. Those two have to stay healthy for San Diego’s defense to thrive.

Bottom line: San Diego’s secondary has the talent and overall depth to be the strength of this year’s defense. Staying healthy and developing chemistry with new pieces in place such as Wilson and Robinson will be critical to this group’s success. “We’ve got a lot of guys that can play a lot of different parts in this defense,” Flowers said. “And it can create havoc for offenses. I would love to just have Jason Verrett out with me this whole season because he’s electric. You need a guy like that on the field. And nothing is going to get him more prepared and better as a player than experience.”