Jose Mourinho believes Andreas Pereira can be a Manchester United great.

The Brazilian midfielder has been loaned out to Valencia in La Liga this summer the United boss insists he will shine at Old Trafford in due time.

“Andreas is already a very good footballer,” Mourinho told the club’s website.

“He is a young player with great natural ability and a good attitude towards continuing his development. I have no doubt that he has the potential to be one of the future great players of this club.”

The 21-year-old has extended his contract at United, keeping him tied to the Old Trafford outfit until 2019 with an option for an additional year.

“I am delighted that I have extended my contract with this great club,” Pereira said.

“The manager is building a great team here and I want to be part of that as soon as possible. I am going to continue my development at Valencia this season in the hope that I will get plenty of minutes on the pitch.

“I would like to thank the manager for his help and guidance and for the faith he has shown in me.”

Pereira spent last season on loan to Granada where he played 35 times in the league, scoring five goals.