Manchester United manager Louis van Gaal reacted angrily to a question about Ander Herrera's situation at the club.

The Spanish midfielder was one of Van Gaal's first signings last summer, with United having paid Athletic Bilbao a reported £24m to conclude the deal.

However, despite having been a regular during the opening few weeks of the campaign, the 25-year-old has not started a game since December 2, which has resulted in speculation regarding Herrera's future at Old Trafford.

When a journalist asked the United boss for an explanation, he responded: "You are asking always about the player who is not playing. Three weeks ago it was Falcao. It's unbelievable. I can only line up 11 players.

"It's not so interesting that you talk about [the fee paid]. Paddy McNair is also important and he cost nothing. I am not discussing [the overlooking of Herrera] with you."

Herrera has made 14 appearances this season, from which he has scored three goals.