Manager Jose Mourinho said Luke Shaw used "his body with my brain" during Manchester United's 1-1 draw with Everton and has told the club's young players they need to "grow up" quickly.
Defender Shaw, 21, made his first appearance since January on Tuesday night and it was his injury-time shot that led to the penalty from which Zlatan Ibrahimovic equalised.
"He was in front of me and I was making every decision for him," said Mourinho.
"He has to change his football brain."
On Monday, Mourinho questioned Shaw's commitment and focus.
Shaw's appearance as a substitute against the Toffees was only his 16th match of the season for United and, while elements of his display pleased Mourinho, the Portuguese had a warning message.
"We need his fantastic physical and technical qualities but he cannot play with my brain," added the Old Trafford manager, who sent on Shaw only after Ashley Young's injury.
"He must accelerate the process. Twenty-one is old enough to have a better understanding. He has a future here but Manchester United cannot wait."
Shaw was left out of the United squad altogether for the draw with West Brom on Saturday, which led to a meeting between Mourinho and the full-back, who signed from Southampton for £27m in 2014.
Former England midfielder Trevor Sinclair on BBC Radio 5 live
If you were doing that to under 10s it would be embarrassing, never mind a full international. I can't believe what I heard last night.
Jose obviously feels he needs more from him but I don't know how much he can take. It's like Luke Shaw's a punchbag at the moment.
I don't know about management at that level but I've got my own kids - in a similar kind of thing, man management - and sometimes you need to put your arm around them. At the moment that's certainly not happening for Luke Shaw, the poor lad.
Rashford is 'desperate'
Shaw was not the only United youngster singled out by Mourinho after United had drawn for the ninth time at home in the league this season.
England striker Marcus Rashford scored eight times in his first 14 Premier League games but has not found the net since 24 September.
Rashford had one early chance saved on Tuesday, although he was flagged offside, and then struggled.
Mourinho says the 19-year-old is suffering from a major lack of confidence.
"The kid is desperate," said Mourinho. "He tries and tries.
"It is not a surprise in the second year. One day I will try to find out if it happened with Ryan Giggs or one of those guys.
"I must not kill him. I have to help him because the kid is phenomenal."
Ibrahimovic coy on future
United had striker Ibrahimovic to thank again as the Swede's injury-time penalty rescued a point which keeps United fifth in the table.
The former Barcelona, Inter Milan and Paris St-Germain striker's contract expires at the end of the season and he is yet to decide whether he will still be at Old Trafford next term.
"We are talking," the 35-year-old told MUTV. "Whether we were far from each other or close to each other, there is no news. There are still talks and let's see what will happen. I am open and nothing is done yet.
"I came here without the Champions League and I came here with the team as it was. It was not a team that was favourite to win. I still came and I came to help. I came to do what I am able to do - to make it better and to bring the team to higher views so let's see what happens.
"I am 35. A lot of things have to be settled. It's not like I'm 20 and I have another five or 10 years. Probably I have one, two, three years so everything depends on what you want and what the club wants, and what the vision of the club is because I said from day one I didn't come here to waste time. I came here to win.
"If you want to win bigger then you have to create bigger."