Retired professional boxer Evander Holyfield said Floyd Mayweather Jr. and Manny Pacquiao will eventually face each other in the ring. He noted, however, that a match will not happen if Mayweather is not confident that he can knock Pacquiao out. 

"Everbody is saying, 'Why doesn't he fight Pacquiao? He'll kill Pacquiao,'" Holyfield was quoted as saying by Boxing Scene.

"Until he believes it, the fight won't happen," he added during a news conference in Manhattan for Zhang Zhilei on Thursday.

Boxing Scene noted that Holyfied has a similar experience in the 1990s when Tyson's jail time and other unwanted circumstances prevented him from fighting Holyfield.

But in their most awaited match, Holyfield stopped Tyson during the 11th round of their match in November 1996. During their immediate rematch the following year, Tyson made a name after he bit Holyfield's ear during the third round of their Las Vegas fight where he was immediately disqualified.

At 51, Holyfield has become the adviser and goodwill ambassador of Dynasty Boxing which promotes Zhilei in his fights.

In the Boxing Scene report, it was noted that Holyfield will help mentor Zhilei who has already grabbed a silver medal during the 2008 Summer Olympics in Beijing.

According to International Business Times, Pacquiao has already repeatedly expressed his desire to fight Mayweather but that the former has failed to show his interest, saying that the Filipino boxer should first opt-out from his contract with Top Rank Promotions and negotiate as a free agent.

The two have been rumored to fight each other for the past years but plans never materialized because of disagreements between their camps.

Arum earlier told Reuters in an interview that the fight will eventually happen. "We are certainly open to the fight happening and we are prepared to sit down with (the Mayweather team) at any time and work out terms," the promoted added.

Pacquiao is scheduled to fight again in November while Mayweather has an upcoming match in September. Both fighters, however, still have no definite opponents announced for their fights.