Ruud Gullit has suggested that Memphis Depay's extravagant lifestyle is to blame for his performances on the field.
The 21-year-old winger joined Manchester United from PSV over the summer in a £25m deal but has managed just two goals in 13 Premier League appearances, with a further three in the Champions League, and has recently found himself dropped from manager Louis van Gaal's starting XI.
Depay made headlines last week when he arrived at United's Carrington training ground in a new Rolls Royce convertible, days after he was at fault in their 2-0 loss at Stoke City.
"I am a fan, and I will keep my faith in him but he must do something about the fact that he has been labelled the worst buy in the Premier League in 2015," Gullit wrote of his Netherlands compatriot in De Telegraaf. "He needs to deliver. He has a lot of qualities, but to fulfil his potential he has to stay low-key in his personal life. If you don't perform, you must not turn up in a brand new Rolls Royce and a new Hummer at the training ground.
"Memphis should concentrate fully on football. It would be a shame if someone like Memphis is going to be wasted because of all this side stuff. He has to make sure they talk about the footballer Memphis. He has to accept criticism as a man and get on with his job as a footballer.
"Don't be satisfied so easily - if you get three chances and you only score once, you have to accept that you really did not play well. At this level, that is not good enough. If you get one chance, you must put pressure on yourself to convert that one chance. That is what the game is about at this level."
Depay was an unused substitute in United's 2-1 win over Swansea City at Old Trafford on Saturday.