"X-Men: Days Of Future Past" star Hugh Jackman admitted he knows his days as Wolverine are numbered.

In an interview with IGN, Jackman explained no one has ever discussed a replacement with him, but knows the production team has talked about it.

"Look, that's inevitable, man," Jackman told IGN. "Anyone who thinks they're indispensable in this business is fooling themselves. But I feel unbelievably blessed to have this part. I never thought in a million years I'd get to play him seven times. Every day I walk on the set with the claws and the hair, I thank my lucky stars. I don't take any of it for granted...I'm sure by the way, that it won't always be my decision to always be here. At some point, someone will close the door on me."

Jackman also explained to IGN the physical demands relating to his "X-Men" character. The actor had to learn some martials arts in order to incorporate a "Samurai element" into the film.

"Here my physical preparation because of Wolverine has been even better for this, because I really haven't stopped for almost two years," Jackman said. "Because I spent a year preparing for that and we shot that for six months and six months later here we are, or five months later. So in a way, physically in terms of the look of the character, I'm probably in better shape than I was for The Wolverine, which has surprised me. But all the action in this, we've done a little bit of it but most of it is yet to come. So right now, I'm feeling pretty good, but I'm sure my body will be beaten up pretty soon!"

You can read Jackman's full interview with IGN here. "X-Men: Days of Future Past" will be released to theaters May 23.