Manchester - Louis van Gaal has challenged young forward Marcus Rashford to show consistency in his Manchester United career following a breathtaking first appearance in the 5-1 Europa League victory over Denmark's FC Midtjylland.
Rashford was only called into the starting line-up for his debut when Anthony Martial injured his hamstring in the pre-match warm-up -- the second successive week United have lost a player in such circumstances after goalkeeper David de Gea pulled out of the first leg.
But the 18-year-old scored two well-taken goals as United won 5-1 on the night, 6-3 on aggregate, to ease through to the last 16 of the competition.
"I've said already a lot of times, that's fantastic for him, but you have to be consistent," said the United manager.
"We are looking for consistent strikers and there are not so many on this earth, but he gave a brilliant performance.
"I didn't have another option so it was easy. He was there on the bench because he was the natural sub for Martial.
"I put (Joe) Riley in there because he is playing left-back in the second team and I have seen him play well, he has been the best player on the pitch, that's what I'm looking at these matches.
"I'm always confident in these players but the first match, they always play well. It is the second or the third match that mostly gives problems. That's why it's a fantastic step for them in their learning process, their development process."
Young full-back Riley was also impressive in the game and van Gaal's mood was helped by the news that Martial's injury does not appear to be too serious.
With an important league game against Arsenal looming, the Frenchman has a chance of being fit for that clash.
"The first impression is it's not serious," said van Gaal who now has 15 senior players injured.
"He is tired and he can be tired because he is 20 and he has played all the matches.
"What is remarkable is he stepped down himself. I couldn't believe it was happening again, it is unbelievable. It is difficult to change or rotate when you don't have any other players.
"I don't think he has a muscle injury because he stepped down when he felt his hamstring was tight. It is ridiculous to lose two players in the warm up against the same opposition, but we have to keep going and we did."
An own-goal by Nikolay Bodurov cancelled out a superbly-taken opener from Pione Sisto for the visitors, who led 3-1 on aggregate with his 27th minute effort.
After Juan Mata missed a penalty just before the interval, the Premier League side finally took control in the second half with Rashford scoring twice and putting United into the lead on aggregate.
In the closing moments, United won a second penalty, converted by Ander Herrera and, following the dismissal of Andre Romer for a second yellow card, man of the match Memphis Depay completed the rout in injury-time.
Depay, whose form has been inconsistent since his summer move from PSV Eindhoven, looked in unstoppable form and van Gaal hopes his countryman can maintain that.
"I am very happy for Memphis," he said. "We need these kind of matches (for him). He played fantastic and he can play fantastic maybe it's a turning point for him, you never know. I hope with all my heart."