Former undisputed heavyweight champion Evander Holyfield is set to finally lay down his gloves on his 50th birthday later this week.

Holyfield will bring down the curtain on a career that spanned nearly 30 years and saw him win the heavyweight title a record four times.

The American, who turned pro after winning bronze at the LA Olympics in 1984, will make a formal announcement on Friday at his birthday party after giving up on his unrealistic dream of securing a world title shot with either of the Klitschko brothers.

"I believe I can beat either of them but I don't have time now to fight my way back up the rankings and become the number one contender," Holyfield said in the Daily Mail.

"There's no point badgering them any longer. If I don't get the call on Friday, I quit."

Bernd Boente, the Klitschkos' manager, confirmed there will be no phone call from the Ukrainian siblings, who between them hold all the heavyweight titles.

"Neither of the brothers will fight Evander," said Bonte. "Both of them would destroy him at his age and they respect him far too much to do that.

"He is one of their idols and that means more than however much money the fight might make."