'Survivor': Boston Rob Mariano Says 'Winners at War' Will Be His Last Season (Exclusive)

Robert Voets/CBS Entertainment

The all-winners season kicks off Wednesday on CBS.

Boston Rob Mariano is going out with a bang. 

The Survivor legend returns for the CBS reality competition's upcoming 40th season, Winners at War -- but after six seasons, he says he's officially retiring from the game. 

"I feel like we have the cherry on top of the sundae this time, and we are officially retired," he told ET on Monday. 

"I'm very content. I'm happy, I'm complete," Rob said. "It's like the ball player coming to the end of a long career. It's bittersweet, but I definitely have enjoyed the ride." 

Rob, who won Survivor: Redemption Island, also appeared on Marquesas, All-Stars, Heroes vs. Villains and Island of the Idols. He'll be competing on Winners at War against his wife, Amber, whom he met on All-Stars. She ended up winning that season, after appearing on The Australian Outback. 

Amber couldn't help but laugh at her husband's claim of retirement. "You'd think! He's done it six times!" she exclaimed. "You can only go six times!" 

However, the mom of four also can't help but say, "Never say never." She's back on Survivor this season after a 16-year hiatus; she told ET she had "written off" ever competing on the series again. 

"How could I not [come back for this season]? Honestly, I don't think any winner would turn down the chance to be on the 40th season. I mean, come on! You'd be crazy to turn it down," she explained of signing on for the landmark season. 

"Don't get me wrong -- it wasn't an easy thing to do. The fact that not only would I be leaving but Rob's leaving again after he was just gone for two months [filming Island of the Idols] before that, it was not easy leaving the girls. That was my biggest concern, but I can't turn Jeff [Probst] down," Amber added. "The fact that he chose me and it's season 40 and I was one of 20 that he wanted, it's a huge compliment. It's a huge honor, so I'm so glad I got to do it."

Season 40 also seems to be Amber's last, while Sandra Diaz-Twine and Ethan Zohn also told ET they're retiring from the game after this season. 

"I think I've gotten more than pretty much anybody [out of Survivor]," Amber said. "Getting to meet my husband, fall in love, getting engaged, being married 15 years. four kids later, going back and doing it again with my husband... I mean, who's gotten to go out there and play with the love of their life two times?" 

"I'm just the luckiest person there is, so I think I should hang up my hat and retire while I'm on top," she added. 

Survivor: Winners at War premieres Wednesday at 8 p.m. ET/PT on CBS.