Trainer Freddie Roach insists Amir Khan can become the first man to defeat Floyd Mayweather.
Khan appears to have landed the biggest fight of his career, with reports suggesting he will face Mayweather on May 3 in Las Vegas.
The British fighter faces a daunting challenge as Mayweather, the sport's No 1 boxer, has held titles in a variety of weight divisions during his unbeaten 45-fight career.
Roach steered Khan to a number of world title wins before he linked up with new trainer Virgil Hunter and has faith in the Bolton man's ring skills.
The respected American believes Khan's searing hand speed will cause the 36-year-old Mayweather problems, but admits he must curb the reckless attacking approach which led to his most recent defeat against Danny Garcia.
Roach told the Ringside Toe 2 Toe Podcast: "That's not an easy fight. I've always said Amir has the right style to beat Floyd if he fights correctly and doesn't stay in the pocket too long.
"I always thought he could beat him with his speed. I think he's faster than Mayweather and that's what it takes to beat him.
"Floyd might have his hands full on the night."
Roach still trains Manny Pacquiao, who remains keen to face Mayweather, despite numerous failed attempts to match the two superstars of boxing.
Rows over blood tests and the purse split have scuppered previous attempts to stage the mega fight and Pacquiao has heard nothing from the Mayweather camp, despite agreeing to his demands.
When asked if Manny still harboured hopes of battling Mayweather, Roach said: "Of course he does. It's the biggest fight in the world for him.
"We all want that fight and Manny especially. Manny's offered a 60-40 split, a blood test, no problems whatever Mayweather wants. We've agreed to anything and he just keeps ignoring us."