Manchester United boss Jose Mourinho and Ander Herrera has seen their relationship turn sour in recent months.

The Daily Mail says Herrera is believed to have innocently invited a friend with close links to Celta Vigo to Carrington shortly before United played the Spanish club in the semi-final of the Europa League.

Mourinho recognised the visitor and ordered Herrera – whose father played for Celta and later became the club's sporting director – into his office for a dressing down.

The change in their relationship has been noticed around the club.

"We used to joke that he was Jose's golden boy, and they were always chatting about the game," said an insider.

"But the dynamic has changed since the end of last season. It's not the same."