Manchester United manager Louis van Gaal has claimed Angel Di Maria is yet to prove his real worth at Old Trafford because he "has to adapt to the English rhythm of the game".
The Premier League giants paid a club record fee of £59.7m to Real Madrid in the summer of 2014 to secure his services after he, alongside Cristiano Ronaldo, led Carlo Ancelotti's side to Champions League glory, while Di Maria reached the World Cup final, having an impressive tournament in the process.
The 26-year-old looked to be the perfect age and in the ideal place to become the leader of the new United era under Van Gaal but he has struggled to replicate the sensational form that lit up La Liga, having scored only three goals in 16 appearances.
Di Maria made an impressive start in the Premier League, scoring three goals and providing three assists in his first five games, while receiving the club's player of the month award for September.
In January, Di Maria admitted struggling, while he asked for more time to fulfil expectations.
"I come from another league and the Premier League is more intense. I am yet to get used to this change. Lately I am playing in a more advanced role and I am feeling comfortable. I hope things go well in the future," he said.
And Van Gaal has also admitted the ex-Real Madrid star is struggling due to the pace of the Premier League.
"Di Maria has to adapt to the English rhythm of the game," Van Gaal told MUTV.
"That's a high standard and the big difference with other countries. He shall do that. I'm convinced of it."
Nevertheless, the manager believes Di Maria is not the only one who will need to give more during the last part of the season.
"You can always improve," Van Gaal insisted. "You can never have a perfect match, which I have said once before in the press conference. You have to improve and every team has to improve, which is why we are training.
"I am happy with the results but I also think we can still improve, that is also the process we have talked about already from my first day. But we have to improve."