The France international endured a campaign of disappointment last time out, starting fewer than half of the Red Devils' league games and recently expressing a desire to move on.
Martial remains a Man United player for now, though, and Herrera insists that the 22-year-old - absent from Les Bleus' World Cup-winning squad this summer - has what it takes to become a global star.
"He's very talented," Sky Sports News quotes him as saying. "He can be one of the best players in the world and I think he is very focused this season to smash it. When you have players like Anthony, like Marcus Rashford, Jesse Lingard, Juan Mata, Alexis Sanchez, those kind of players that can change the game.
"If one of them cannot play, we have three or four more so we have lots of options. I think we shouldn't think that any other club in the Premier League has better players because at least we have as good as the opponents.
"Now it's all about work, confidence, about keep playing like he did today. I am confident with them because they are all amazing players and Anthony looks very sharp."
Martial played the opening hour of Man United's first pre-season outing - a 1-1 draw with Club America in Arizona.