It's not unusual for the famous to visit legendary boxing trainer Freddie Roach's Wild Card Boxing in Hollywood, Los Angeles.
But Roach admitted he did a double take when Floyd Mayweather arrived unannounced - not once but twice.
In news that will fuel speculation of a "Fight of the Century" rematch with his famous charge Manny Pacquiao, Roach still believes Mayweather's decision to suddenly appear at his popular gym was to fish around if there was interest in a second fight.
Fans arrive from around the world and all walks of life to visit Roach's Hollywood gym which caters from his most well known charge, 11-time world champion Pacquiao, to Hollywood actors like Mickey Rourke to 12-year-olds simply wanting to learn to box.
Still, Mayweather stood out when he gave Roach a visit.
Roach was not sure whether it was a concrete sign that Mayweather wanted a rematch with Pacquiao after May 2015's underwhelming "Fight of the Century".
The bout - claimed by Mayweather by unanimous points - was not much of a spectacle but still grossed more than $600 million worldwide, making it the biggest event in boxing history.
Roach is preparing Filipino great Pacquiao for Sunday's WBO welterweight world title fight with Australia's Jeff Horn in Brisbane.
And Mayweather has August's super fight with UFC champion Conor McGregor.
But Roach did not rule out another shot at Mayweather for Pacquiao in the future, not since the American's recent fascination with his gym.
"Maybe eventually he will come to the table," Roach said of a Mayweather rematch. "Mayweather has come twice to my gym now - it's unusual.
"I said 'do you want to talk about Manny or anything like that?', and he said 'no, I just wanted to see the gym'. He said 'I might franchise these around the world', and I was like 'oh, ok'."
"He (Horn) can derail us really badly. Manny is, I think, in a must-win situation. He wants a rematch with Mayweather. And I mean to get Mayweather you have to look good against Jeff Horn, he has to look good, he has to be impressive. I think there is a lot riding on this fight and I feel Manny has to look really good in this fight and the way the training camp went, I think he will."
Roach said he had gotten to know Mayweather thanks to the surprise visits but admitted he wasn't sure whether the undefeated American had an ulterior motive.
"I don't really know what he is up to but he does come to visit from time to time, which is surprising," he said.
"But he's not a bad guy one on one. Give him a TV camera and maybe that will change."