Former Manchester United striker Dwight Yorke has called on Marouane Fellaini to 'prove that he has what it takes' to represent the Red Devils.
The Belgian international has been the subject of much criticism from Man United's own supporters this season, while his physical approach on the field has also led to negativity.
Yorke has admitted that the £27m midfielder has struggled to 'live up to expectations' at Old Trafford, but has insisted that the 28-year-old is "a very good player".
"He certainly came with a big price tag. He was outstanding at Everton, and since he has come to Manchester United he has struggled and hasn't lived up to expectation," Yorke told Sky Sports News.
"We know he is a very good player, but one thing when you come to United is you have to go from being a good player and go on further - you need to bring something totally different to the team. We expected that from Fellaini, but it hasn't quite happened.
"The critics are still out, there's still uncertainty on whether he passes the test of being a Manchester United player."
Man United will return to Premier League action away to Manchester City on Sunday afternoon.