(CNN) -- Boxing great Oscar De La Hoya says he's back in rehab.
It's not the first stint in rehab for De La Hoya, 40, who has previously spoken about problems with drug and alcohol abuse.
The world-champion boxer announced he had entered treatment just days before Canelo Alvarez, who De La Hoya's Golden Boy Promotions represents, is set to square off against Floyd Mayweather.
"Canelo Alvarez and I have big fights coming up this weekend. His is in the ring and mine in treatment," De La Hoya said in a written statement Tuesday.
"I will not be at the fight to cheer Canelo to victory since I have voluntarily admitted myself into a treatment facility."
He said he had explained the situation to Alvarez.
"He understood that my health and longterm recovery from my disease must come first," De La Hoya said. "Thank you for your understanding. I ask for your support and privacy during this difficult time for me and my family."
CNN's David Close contributed to this report.