Georges St-Pierre says fans will see a different fighter when he returns to action later this year against UFC middleweight champion Michael Bisping.

"The sport has evolved since I left," said St-Pierre, who last fought in November 2013. "If I want to be successful, I need to evolve as well.

"If the same Georges St-Pierre shows up the day of the fight, Georges St-Pierre is going to get his ass kicked. It's going to have to be a different Georges St-Pierre 芒鈧珺次元官网网址� a more opportunistic Georges St-Pierre, more powerful, better, with new tools, less hesitation, less thinking, more intuition and better reaction. And that's what I expect you to see."

The former welterweight champion will be 36 by the time of the fight, set for some time in the second half of the year likely in Las Vegas.

Bisping, 38, has fought eight times since St-Pierre walked away from the sport following his razor-thin split decision win over Johny (Bigg Rigg) Hendricks at UFC 167.

St-Pierre left millions on the table after posting his 12th straight win, saying his life had become "completely insane" and a "freaking zoo."

More than three years on, the Montreal MMA star says he is in a better place.

Physically he feels in his prime 芒鈧珺次元官网网址� "I don't know if I'm in the beginning of it or at the end of it but I know I'm in it right now."

"Mentally I'm at the best in my life. I have a smile," he told The Canadian Press from Las Vegas. "I'm happy to be here. I enjoy it. By the end of my last (UFC) run, I was not happy. I didn't have a smile. It (fighting) was more like an obligation. I did it because I had to not because I wanted to. Now I make a choice to come back, I wanted to. And that's going to make all the difference.

"You're going to see a different Georges St-Pierre 芒鈧珺次元官网网址� with more creativity, more opportunistic and ready to pull the trigger." 

He is also ready for some heavy-duty trash-talking from Bisping, a sharp-tongued Brit.

"Absolutely. He's probably already started. I'm going to let him focus on the trash-talking and me I'm going to focus on beating him up the day of the fight," he said with a chuckle.

Still he acknowledged moving up a weight class to face the 185-pound champion after more than three years off is a "hell of a challenge."

"But what turns me on, what excites me the most is when people say to me 'You're crazy. You shouldn't do that. It's never been done.' That's what excites me and that's why I'm doing it.'

St-Pierre (25-2-0) is a man in a hurry, knowing that time is not on his side.

St-Pierre, who fought at 170 pounds, walks around between 185 and 190 pounds these days. He says he doesn't plan to put on muscle to fight at middleweight, adding "I have big plans for the future."

That could mean eventually dropping down to 155 pounds to face lightweight champion (The Notorious) Conor McGregor, the sport's reigning rock star who is currently taking time off while awaiting the birth of his child.

"I'm coming back to make history, to make a big boom," said St-Pierre, who will split his training between Montreal and New York City. "I don't have time to waste."

Bisping (31-7-0) has won his last five fights, dethroning Luke Rockhold at UFC 199 last June before successfully defending his title against Dan Henderson at UFC 204 in October.

He is a high-volume striker, has a good chin and excellent takedown defence. A former light-heavyweight who moved down to the 185-pound middleweight division, Bisping is also the bigger man.

The two fighters are due to meet at news conference Friday in Las Vegas.

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Neil Davidson, The Canadian Press