While much has been written and said about the dynamic turnover of the Patriots defense this offseason, no position has undergone greater change than the secondary.

Three of the four players who started at defensive back for the Patriots in the 2008 opener — cornerbacks Ellis Hobbs and Deltha O’Neal and safety Rodney Harrison — have either been traded, been released or retired. The only holdover is safety James Sanders.

While Sanders and Brandon Meriweather (who moved into a starter's role in late October after Harrison’s injury and never looked back) figure to get the call at safety this year, there is a more dramatic change at cornerback. Newly acquired veterans Leigh Bodden and Shawn Springs were added to a unit that includes second-year corners Jonathan Wilhite and Terrence Wheatley, as well as rookie Darius Butler.

There is no substitute for continuity — to that end, the Patriots secondary has spent a lot of time hanging out together since first coming together in the spring, trying to build the level of familiarity you need to be successful as a unit.

“Guys have been a real tight-knit group,” said the 27-year-old Bodden. “We’ve been hanging out, talking about things, just seeing what we think our secondary’s going to be. There’s a lot of things that go into it and there’s no timetable. It’s just how well guys mesh together, and I feel we’ve meshed together well ever since [organized team activities].”

Bodden has taken charge at one cornerback spot and has the inside track to get the start at right cornerback when the Patriots open their season Monday night against the Bills. His time in Cleveland with former Pats defensive coordinator Romeo Crennel has given him a leg up in the transition process — the 6-foot-1, 193-pound Bodden has appeared comfortable in the New England system.

His physical style certainly has opened the eyes of Patriots coach Bill Belichick.

“I think he does have a good physical style. He’s a big kid,” Belichick said of Bodden, who signed with the Patriots on March 11. “He’s tough. He has long arms. He’s good when he can get his hands on the receivers. He has good playing strength. I would say he’s a physical corner. He’s a good tackler and he jams receivers well. I think he has a physical style, yes.”

The other cornerback duty will likely go to either Springs or Wilhite, with Wheatley and Butler providing depth. With the opener against Terrell Owens and the Bills looming, Springs is an intriguing figure, especially when you consider his long history against the occasionally combustible wide receiver. As for Wilhite, a strong finish to the 2008 season, a mostly positive training camp and preseason and some uncertainty concerning Springs’ knee and preseason could give him a edge.

The CBs have struggled — the Patriots ranked last in the NFL in passing yards allowed in the preseason — but Bodden believes the longer this group of corners plays together, the better they will be.

“It is definitely important to know how guys play, what they like to do, their strengths, weaknesses … you really have to know that and you’ve just got to get to know players off the field as well to trust them and just know what kind of person you’re playing with,” Bodden said. “It’s definitely a huge part of the success of a defensive backfield: The closer you are, the harder you’ll play for each other, and it makes for a great secondary.”