
By TMZ Sports
Golden Boy Promotions President Oscar De La Hoya would be a complete fool to come out of retirement and fight again at 42-years-old ... so says his legendary former promoter, Bob Arum, who's telling Oscar -- DON'T COME BACK.
De La Hoya has been flirting with the idea of getting back in the ring and fighting WBA/IBO middleweight champion Gennady Golovkin ... but Arum says it would be a - "terrible, terrible mistake."
"He had a great career ... when it's over, it's over."
Arum says Oscar should learn from guys like Sugar Ray Leonard ... who tried to come back at 40 years old ... and looked bad.
"I don't think Oscar is fool enough to do that."
De La Hoya has been retired since 2008 when he was stopped in a one-sided fight by Manny Pacquiao.