The Spanish midfielder has backed the French winger to become one of the elite players this season at Manchester United
Anthony Martial can become one of the best players in the world, according to to Manchester United team-mate Ander Herrera.
The French winger scored 11 goals in all competitions last season, but was used sparingly by manager Jose Mourinho, completing 90 minutes just six times in the Premier League.
Indeed, the 22-year-old was left out of France's World Cup-winning squad after a patchy season.
Martial's agent subsequently claimed earlier this summer that Martial wants to leave United, with reports linking the attacker with a move to Chelsea, who are braced for the prospect of losing Eden Hazard to Real Madrid, or Bayern Munich.