Cotto lost out via a points decision to Mayweather after giving a decent account of himself at the MGM Grand but was never able to secure a second helping.
Roach, speaking at the announcement of Cotto’s return to action against James Kirkland on February 25 in Texas, outlined the complete faith the Puerto Rican has had in the American since both teamed up in 2013.
“Miguel always tells me if I was in his corner when he fought Mayweather, we would have won.” Roach said before commenting on which big fight could follow a victory over Kirkland.
“What’s next? Who knows? But right now we have a tough fight in front of us. And we’re getting ready for that fight. I did send my guys out a couple of times to work with Miguel in Puerto Rico just to keep him fresh.”
On how Cotto is looking in the gym, Roach added: “He’s tremendous. He works hard. If he didn’t look great in the gym, I wouldn’t let him fight. I care that much about him.
“He will be 100% ready for this fight and if he’s not 100% for this fight, it won’t happen.”
Kirkland is widely seen as a stepping stone for Cotto as the veteran has enjoyed better days in the past despite still only being 32.
It’s been almost five years since Kirkland pulled off an eye-catching victory that would have seen him move up in the ranking, meaning defeat against Cotto could well leave the southpaw with nowhere left to go.
