Valencia has been in the North West since 2006 when he joined Wigan Athletic from Villarreal before then completing a £16m move to Manchester United in 2009.
However, new manager Van Gaal, who can speak four languages, is not impressed with the standard of the wide player's English according to the Daily Mail.
The paper says that Valencia has been told to take English lessons with the rest of the squad's Spanish speakers.
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United have added four Spanish speakers to their squad this summer – with Argentines Angel Di Maria and Marcos Rojo, Colombia's Radamel Falcao and Spain's Ander Herrera joining the club.
All four are taking English lessons, as is goalkeeper David De Gea, with Valencia ordered to join them.
Juan Mata is the only Spanish player at the club deemed to have good enough English that he does not need the lessons.
The Mail says, Di Maria and Rojo 'barely speak a word' of English and will join a beginner's class. Falcao and Herrera are to join De Gea's intermediate class in the next few months, while Valencia is getting one-on-one tuition.
Valencia's lack of English is perhaps a bit more understandable when you learn a little about his background.
He grew up in a poor part of Ecuador and had to share a bungalow with his parents and five brothers and one sister.
A notoriously shy character, he has never conducted an interview in English during his time at Old Trafford.
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