Jose Mourinho claimed Marcus Rashford is lacking confidence after watching the youngster fail to score again in the Premier League as Manchester United drew with Everton on Tuesday night.
The 19-year-old has scored seven times this season but hasn't found the net in the top flight since September.
Mourinho criticised Rashford and United's forwards after Saturday's stalemate with West Brom at Old Trafford but was more forgiving of the teenager after the draw with Everton, the Manchester Evening News report.
"We have people that are not getting the opportunity and that's bad for the team," Mourinho said. "I speak with them because when you give absolutely everything and leave the pitch absolutely dead of work that's fine for me that's fine for me.
"Marcus Rashford doesn't score a [Premier League] goal since September, the only thing he deserves is support, nothing else, no critics, support. He works, he works, he works, he tries, he tries, he tries. He plays through the middle, he plays on the left, on the right, through the middle, he tries.
"So just as an example I have to support the boys and hopefully in the Europa League we score enough to go through the next round and it is something we have to improve next season."
When asked if Rashford was specifically lacking confidence, Mourinho replied: "It's easy to see and the kid is desperate, he tries.
"And it's not a surprise for me, the second year after the first one by surprise, it's something maybe one day I will try to find if it happens the same with some Ryan Giggs or some of these guys, they appear as a kid and then the next year probably it's not the same.
"But the kid is phenomenal, amazing professional, amazing professional, so no problem I told him just now. No problem. Keep going."
Zlatan Ibrahimovic spurned a presentable chance with the game goalless early on and Mourinho feared the pattern of previous home games would continue.
"The game always starts with a big chance missing," he added. "Always always, always. We always have a chance in the beginning of the game where you are facing the keeper and the keeper saves and you miss or something happens and that is happening all season.
"We have lots of unlucky decisions by the referees, we have had lots of amazing performances by the goalkeepers, we have had lots of ultra defensive teams coming here, but we need to score goals because we have chances and we need to score goals. It's difficult."