They re-signed middle linebacker Jonathan Vilma, which was a key to their off-season plans, and a week later were able to sign cornerback Jabari Greer away from the Buffalo Bills -- another important piece of the puzzle.

On Wednesday, the Saints filled another important spot when Minnesota Vikings free safety Darren Sharper agreed to a deal to be the "quarterback" on that side of the ball for new defensive coordinator Gregg Williams.

Sharper, a four-time Pro Bowl pick in his 12-year NFL career with the Green Bay Packers and Vikings, brings a wealth of playmaking ability to the Saints' secondary -- which has been torched time and again by the deep ball in the last two seasons.

Sharper, 33, leads all active players with 54 interceptions, returning eight of them for touchdowns -- which is tied for fifth in NFL history. He has forced nine fumbles and recovered seven, with two being returned for scores.

While Sharper is getting up in age, the Saints needed a free safety of that ability after Josh Bullocks, who is now with the Chicago Bears, and Kevin Kaesviharn struggled there as the starters the last two years.

Williams repeatedly identified the free safety position as one of the most important on the field, saying the free safety and middle linebacker are the "quarterbacks" of the defense.

He also said earlier in the week that Sharper, who had visited with the Saints early in the free agency signing period, was a player he's always "liked from afar."

Saints General Manager Mickey Loomis is confident that Sharper has a lot left in the tank.

"No. 1, you have to look at his resume and how long he's been in the league, the success that he's had," Loomis said. "If you look at what we have got at the back end, most of our guys are in the front end of their career.

"Adding some experience to that group with a veteran who's had some success -- a lot of success, really -- can be very valuable to us."