Dan Henderson has admitted he did not think old rival Michael Bisping would ever have the ability to become a UFC champion.
Lancashire's Bisping became Britain's first UFC title-holder in June when, with just 17 days' notice, he stopped Luke Rockhold in the first round of their middleweight fight.
Bisping told Sky Sports afterwards about his preference to defend the belt in Manchester in a rematch against Henderson, who beat him seven years ago, a request which has been granted.
His upcoming challenger, however, has confessed shock at the turn of events.
"I thought he was good enough to beat certain people - but certain people he'd have trouble with," Henderson said in an exclusive interview with Sky Sports.
"He's always lost the key fights and had to build himself back up. Then he'd almost get a title shot, but lose again.
"He's had that kind of career - he was almost there for a long time. I was like everybody else, I wasn't sure that he'd ever make it."
Henderson, 46, has admitted he predicted Bisping would fall short when replacing the injured Chris Weidman at short notice to challenge for Rockhold's world title.
The American veteran, feted for the one-punch knockout power that flattened Bisping in 2009, is still unwilling to accept the Brit has ironed out his flaws despite becoming world champion.
Asked if he was shocked by Bisping's finest moment, Henderson said: "Yeah, absolutely. I thought Rockhold was a really bad fight for Bisping style-wise.
"Michael has never been known as a knockout guy. He can outpoint people and out-condition people, but I didn't think he was going to outpoint Luke on their feet. Luke is always in good shape, also, so I didn't think it was a good match-up.
"But Michael showed he had some knockout power, I guess. It's hard to say if he truly has knockout power or if he just caught [Rockhold] perfectly on the button, because that doesn't take much.
"I didn't expect [to rematch Bisping]. I didn't expect a title shot, let alone against Michael Bisping. Two unexpected things happened but I'm welcoming it."