Errol Spence Jr. thinks it would severely hurt his credibility if he fought Manny Pacquiao at this point in his career, and he has a specific historical precedent in mind to back up his claim.

Talk of Spence, of Desoto, Texas, fighting Filipino legend Pacquiao cropped up recently after Pacquiao, 44, indicated that he was keen on coming out of retirement to fight the IBF, WBA, and WBC147-pound champion. The two, in fact, were originally supposed to fight last summer but Spence suffered an eye injury less than two weeks before the night of the fight. Pacquiao ended up fighting—and losing to—late replacement Yordenis Ugas, whom Spence wound up stopping earlier this year by 10th-round technical knockout. Pacquiao announced his retirement last fall ahead of a bid to run for his country’s presidency. Earlier this month, Pacquiao participated in an exhibition bout in South Korea against martial artist DK Yoo.

When asked recently if he would consider reciprocating Pacquiao’s interest in a fight, the 32-year-old demurred, essentially saying that such a matchup today would be a gross mismatch. Spence cited the 1980 heavyweight title bout between Muhammad Ali and Larry Holmes as an example of why fighting Pacquiao could potentially cripple his legacy.

Ali-Holmes is regarded as one of the saddest valedictions in sports. The 38-year-old Ali was a mere husk of his once dynamic self in that fight, and Holmes, eight years younger, battered The Greatest from pillar to post for 10 rounds before Ali’s trainer, Angelo Dundee, mercifully stopped the bloodbath. Spence believes that that fight damaged Holmes’ reputation and is why he thinks Holmes, who made 20 defenses of his heavyweight title, is somewhat overlooked today. In other words, Spence thinks a Pacquiao fight would be a one-sided affair in his favor that would offer virtually zero upside.

“I wouldn’t fight him, I probably wouldn’t fight him,” Spence said of Pacquiao in an interview with ESNews. “I wouldn’t fight him. Like you can see the stigma that—Larry Holmes is one of the greatest heavyweights of all time. One of the greatest fighters of all time. I feel like he don’t get the respect that he deserves. Or like people just don’t regard him. People really don’t just talk about him.

"I think that’s all because how he beat Muhammad Ali—he f---ed him up in that fight. I don’t really think people consider him [elite]. Nobody really talk about Larry Holmes. I think it’s all because of that.”