By TMZ Sports

Don't rule out a fight between Oscar De La Hoya and Gennady 'GGG' Golovkin -- because after De La Hoya called out Triple G last week ... the IBO/WBA middleweight champion's rep tells TMZ Sports - "stranger things have happened."

GGG's rep says the boxer is well aware of the TMZ Sports video in which 42-year-old Oscar says he thinks about making a comeback every day -- and has his sights set on Golovkin.

But Gennady didn't take the call out as an insult ... his rep says, "It was a show of respect."

In fact, GGG and De La Hoya came face-to-face just days after the video and had a very friendly exchange ... even taking a picture together.

GGG's rep says the boxer is so dominant, he has trouble finding opponents -- "We can't even get guys to return our calls."

De La Hoya, the President of Golden Boy Promotions, has been retired since a 2008 knockout loss to Manny Pacquiao, but he created shockwaves when he initially appeared on a Los Angeles radio show and revealed that he's seriously considering the possibility of returning to the ring.

Two days after his radio appearance, he stirred the pot even further by telling TMZ Sports that his preference, for his comeback opponent, would be Golovkin.

Whether or not De La Hoya is actually serious about a comeback remains to be seen.