FOXBOROUGH, Mass. -- Two of the top three spots at safety have been turned over, and two new cornerbacks are filling out the depth chart. No doubt, this is a new look for the New England Patriots' secondary.

How it all unfolds will be one of the more interesting subplots when the Patriots visit the Miami Dolphins on ESPN's "Monday Night Football" (7 p.m.) to kick off the 2011 season.

The biggest questions are who plays most at safety alongside Patrick Chung, who enters as the third defensive back and which defensive back lines up in the slot in those situations?

Second-year safety Sergio Brown looks primed to step up his game to the next level. Elsa/Getty Images

Let's examine the candidates.

Arguably no position has been under a brighter spotlight than safety, and it makes sense. Last season, Brandon Meriweather ranked third on the team in playing 80 percent of the defensive snaps, while James Sanders was sixth at 71 percent. Both are gone now, so that's a significant void to fill.

Coach Bill Belichick has gushed at times about second-year safety Sergio Brown (6-foot-2, 210 pounds), who looks primed to take the next step in his progression. He joined the Patriots as a rookie free agent last year with a reputation as a special-teamer, opened the year on the practice squad, was promoted in late October and ended up playing 86 snaps on defense.

In his weekly appearance on sports radio WEEI this week, Belichick said Brown "has just done nothing but improve in the year and a half that he's been here." Brown, like Chung, is considered a hard worker who does things the right way.

Next in line comes Josh Barrett (6-2, 230), who entered the league as a seventh-round draft choice of the Denver Broncos in 2008. Like Brown, Barrett opened his rookie season on the practice squad, was promoted in late November and logged starts in the final three games of that year. Most of his playing time in 2009 came on special teams, and when he sustained a shoulder injury in training camp in 2010, the Broncos waived him with the intention of placing him on injured reserve before the Patriots swooped in.

Barrett spent all of last season on injured reserve before returning to action for the first time in this year's preseason finale.

"He's big, he's fast," Patriots director of player personnel Nick Caserio said. "In Denver, he played defensively and in the kicking game; we felt he was a good football player, and it was an opportunity for us to improve our team. That's why we went and made the decision that we did."

Five-year veteran James Ihedigbo (6-1, 214) rounds out the depth chart, and at this time, he projects more as a core special-teamer than a big presence on defense.

It's a young group, with the 5-11, 212-pound Chung, now in his third season and having gone from playing 20 percent of the snaps as a rookie to 72 percent last year, in position to take the reins.

"I really like Chung; I think he's a player," said former Patriots safety Tim Fox (1976-81), who knows a thing or two about what it takes to play the position. "He's all over the field, high-energy, the type of guy I'd like to play with. Where Meriweather took bad angles at times, you don't see that from Chung. He's a talented kid."