NEW ORLEANS (AP) — Darren Sharper takes some good-natured ribbing from teammates about his age and his supposed declining ability.

When asked about Sharper’s three touchdowns on interception returns this season, Saints strong safety Roman Harper deadpanned, “It’s taken a lot of blocking to get him there.”

Humor comes easily for unbeaten teams, and there’s no question that the 33-year-old Sharper, who signed a one-year free-agent contract with the Saints last winter after being let go by the Minnesota Vikings, is a big reason New Orleans (6-0) is the last undefeated team in the NFC.

“It’s one of those things where you look at him and you say he’s past his prime, you know, 30-something years old, can he still play?” Saints middle linebacker Jonathan Vilma said this week. “He’s doing a great job for us and it’s one of those things that, we knew what we had in him and we just needed to get him here and now he’s showing everybody else.”

Sharper had only one interception in 2008, which raised questions over how many good years the four-time Pro Bowl safety had left. Sharper believed his relatively low takeaway total last season was partly a fluke and partly a result of the Vikings’ disciplined defensive scheme, which required him to remain in a certain area.

Sharper had no issues with the scheme in principle, but said it did not suit him well.

“If I’m in one position the whole game, teams know where you are,” Sharper explained. “They know, OK, this is a guy back there that if we throw in this area, pretty much he’s going to intercept the ball, so we won’t go over there.”

The statistics seem to back him up. Sharper had only five passes defended last season in Minnesota, tying his lowest figure since his second season as a starter in 1999.

He has eight passes defended and six interceptions already this season, putting him well on his way to his fifth Pro Bowl invitation. Sharper often talks of the Saints’ defensive scheme under new coordinator Gregg Williams as one that “takes the handcuffs off,” putting the “free” back in free safety.

“I’m allowed to move around so much and play so many different parts of the football field, it’s kind of hard to peg, not just myself but any of our defenders, on where they’re going to be,” Sharper explained. “So a lot of times you’re able to catch teams by surprise. And when they don’t think you’re going to be somewhere, then you’re there, next thing you know — big play.”

An undrafted free agent out of William & Mary, Sharper has emerged as one of the best big-play defenders the NFL has ever seen.

His 11 career interceptions for touchdowns and 1,353 yards in career interception returns rank second all-time behind Hall of Famer Rod Woodson, who had 12 interceptions for scores and 1,483 return yards.

And Sharper’s totals would be more if Vilma’s roughing-the-passer penalty hadn’t wiped out an interception returned for a touchdown against the Giants’ Eli Manning a couple weeks ago.

Still, Sharper’s 42-yard touchdown return at Miami a week ago set the Saints’ single-season record for touchdowns on interceptions. He also has touchdown returns of 99 and 97 yards, and his 317 return yards this season have already smashed the previous franchise single-season record of 198 set by Gene Atkins in 1991. He is one more good return from breaking Ed Reed’s 2004 NFL record of 358 yards.

Now in his 13th season, Sharper is the active league leader in career interceptions with 60, still a ways from the 81 by all-time leader Paul Krause, who played for the Washington Redskins and Vikings.

Sharper has been so productive this season that his numbers rival those of some Saints offensive regulars. His return yards are only 2 fewer than running back Reggie Bush’s total yards from scrimmage. Both have three TDs.

Whoever doubted Sharper’s ability to play as he did in his prime can say little at this point, though Sharper said he takes no satisfaction in that.

“From playing so long, my career kind of speaks for itself,” he said.

“So it’s one of those things where when you get to a certain point in your career you don’t have to prove anything else. The only thing I want to prove to myself is I can win a Super Bowl ring and that’s the main question I have and that’s why I came here.

“I wasn’t trying to be a big-time free agent acquisition and be a guy that they think is going to change everything and be the savior,” Sharper continued.

“I just wanted to be one of the pieces to the puzzle, and I think I’m being a pretty good piece right now and I want to keep doing that and keep assisting us at winning games.”