Jose Mourinho has warned Anthony Martial "great potential" is not enough as the Manchester United manager needs the forward to start delivering what he wants.
Having started so impressively after his big-money move from Monaco in 2015, the 21-year-old's second season at OId Trafford has been a struggle.
Martial has scored seven goals this term and been left out of the United squad entirely on occasions, including Sunday's impressive 2-0 win against Premier League leaders Chelsea.
Mourinho confirmed his omission was down to dissatisfaction rather than injury, calling on Martial to take a leaf out of 19-year-old team-mate Marcus Rashford's book.
"You know, we have been together for almost 10 months or something like that," the United boss said ahead of tonight's Europa League quarter-final second leg with Anderlecht.
"The same way I know the players much better now, the players they should also know me much better now.
"The same way I know what the players like, I think the players also know what I like.
"The same way I have to go in the direction of the players, the players they have also to come in my direction and that's the point.
"That's why Marcus Rashford, even without scoring goals, even without being since September scoring a goal in the Premier League, even without that he was always a player that I trust.
"He was always a player that I play, always a player that I support because he was always coming in my direction, in the direction of what I want from a player, what I want as a Manchester United player, so I think it is about that.
"It is about getting to know each other better and better and better, and go in the direction of the things that we like.
"So do I think Anthony is a player with great potential? Yes, I think.
"Do I think he can play successfully for me? Yes, I think. But he needs to give me things that I like very much."
It is not the first time Mourinho has expressed frustration about Martial after earlier this month criticising the forward, along with United's other attackers, for their toothlessness in the 0-0 draw with West Brom - the France international's last start.
The attacking quartet that day also included Henrikh Mkhitaryan, who last week in Belgium scored in a fourth successive European trip as United drew 1-1 with Anderlecht.
The away goal could be crucial in this quarter-final clash but the Armenian appears to be another attacking player frustrating Mourinho, having struggled to replicate his Europa League form on the domestic front. Twice asked if Mkhitaryan was fulfilling his full potential, on both occasions Mourinho said: "In the Europa League, yes."
Mkhitaryan and Martial trained with the United squad on the eve of the return leg against Anderlecht, as did captain Wayne Rooney (above).
The 31-year-old trained last Wednesday at the Aon Training Complex but did not travel to Belgium, nor was the forward involved in the squad that faced Chelsea.
"He is working now, he is improving," Mourinho said. "And if in the training session the answer is positive, I would select him to be on the bench tomorrow.
"His experience, his know-how of this knockout phase, I think is a player who can be useful. If we need a goal, he can help us. If we need to keep a result, to keep the ball, to keep control by having possession, he can help us, too, so hopefully his answer in the training session is positive."
Juan Mata, Chris Smalling and Phil Jones are definitely out of a quarter-final clash that Sergio Romero will start instead of first-choice goalkeeper David De Gea. "He is my goalkeeper for tomorrow and he was my goalkeeper in other matches, but he is not my goalkeeper for the Europa League. I never like to do that, complete separation."