Joe Gallagher, trainer of WBA super middleweight champion Callum Smith, warns that Canelo Alvarez must "put up or shut up" when it comes to a showdown with his boxer.
Last December, Canelo moved up to 168-pounds and blew away Rocky Fielding in three rounds to capture the WBA "regular" title.
This past May, he moved back to 160 to unify the IBF, WBA, WBC middleweight titles with a twelve round decision over Daniel Jacobs.
After that win, Canelo named Smith as a potential opponent for the fall.
Smith did his past last month, when he crushed Hassan N'Dam in three rounds on the Anthony Joshua-Andy Ruiz Jr undercard at Madison Square Garden in New York.
Besides Smith, Canelo has also eyed WBO light heavyweight Sergey Kovalev, WBO junior middleweight champion Jaime Munguia and WBO middleweight champion Demetrius Andrade.
According to Gallagher, if Canelo doesn't fight Smith this year, he doubts the fight will ever happen.
"I think the Callum Smith-Canelo fight has to happen either now or in December," said Gallagher to Sky Sports. "If it doesn't happen then, then I don't think it will ever happen.
"Canelo needs to win a genuine 168 world title and Callum is the No.1 and I think that's the fight that makes sense. The fans want to see it, you've seen social media blow up, Daniel Jacobs was hugely impressed ringside, Triple G was. Canelo - it's about time, I don't disrespect him, he's a good fighter, I'm well aware of him but I'm hugely confident in Callum Smith beating him.
"But you can't turn around and start mentioning people and names and then not take the fight up, so it's time to put up or shut up and we'll crack on with our career. If you want to fight Callum Smith, then make an offer, if you don't then forget about it and it will never happen and we'll move on and do what we need to do."