Manchester United manager Louis van Gaal suffered a major blow just one day into his reign as England midfielder Michael Carrick was ruled out for up to three months after ankle surgery.

Carrick suffered left ankle ligament damage in training earlier this week and had an operation on Thursday.

The 32-year-old, who was left out of England's World Cup squad, had appeared likely to be a key part of van Gaal's plans in the Dutch coach's first season at Old Trafford.

But the former Netherlands boss will now have to wait longer than he would have liked to see him in action.

"Michael Carrick has had surgery this morning on his left ankle ligaments and will be out for 10-12 weeks," United said in a message on their official Twitter feed.

Van Gaal had revealed Carrick's injury, without saying the precise nature of the problem or the likely length of his absence, at his first United press conference earlier in the day.

"Michael Carrick was injured a day or two ago so that's a big blow, because he is an experienced player," van Gaal told reporters.

As he stood up to leave the media briefing at Old Trafford, van Gaal responded to a follow-up question by saying Carrick would be out for "a long time, too long".