Manchester United boss Louis van Gaal has insisted that midfielder Ander Herrera must improve if he wants to be considered for consistent first-team selection.
The Dutchman wants the Spaniard to prove he deserves a first-team place ahead of others like Wayne Rooney, Juan Mata and Angel di Maria.
"I have to compare him with people like Rooney and Mata, for example, so that's difficult, they are all at a high level - he has to improve," the 63-year-old told reporters.
"But he's a great guy, he's a very great professional also, so that's not the problem - his problem is he has to compete with high level players and Rooney is also the captain so he has a privilege.
"So then the other places are the place of the position in this system that we are playing now with a number 10 and that's Mata and that's Di Maria. That's difficult to compete against but he did already know that at the moment that he signed for Manchester United."
Herrera has only made 12 appearances since his £29m move from Athletic Bilbao in June.
