Manchester United interim manager Ralf Rangnick said Marcus Rashford was "not happy" with his poor run of form, and urged the forward to take inspiration from team mate Jadon Sancho's recent resurgence.
Rashford, who made his return from shoulder surgery in October, has had one of his worst seasons and was desperately poor in United's midweek 1-1 draw with Atletico Madrid in the Champions League.
"I am pretty sure he is not happy with his performance right now, but it doesn't help if we discuss that every week and talk about our thoughts about what it might be," Rangnick told a news conference ahead of Saturday's game against Watford.
"In training he is in top form, that's why I decided to play him (against Atletico). Now it's about having that transformation from training performance to the competition in the league and this is the next step he has to take.
"We had a very similar situation with Jadon (Sancho) six or seven weeks ago. He is the best example of what can happen. It's the player himself who has to perform and get the best out of his own performance."
United are fourth in the Premier League, a point ahead of Arsenal but having played two more games than the London club.