Ruud van Nistelrooy described Amad Diallo's attitude as "incredible" after he was rewarded for his patience with a match-winning double in Manchester United's 2-0 Europa League win over PAOK.
The winger had not started a game for the Red Devils since October 3 but made the most of his opportunity by scoring twice in the second half following an insipid opening 45 from the hosts at Old Trafford.
Amad's double was his first Red Devils brace, while five of his six goals in all competitions for United have come at Old Trafford.
Interim boss Van Nistelrooy, who has one more game in charge before handing over to Ruben Amorim after the international break, was full of praise for Amad, who also scored his first Europa League strikes since March 2021.
Speaking to TNT Sports, he said: "I think Amad made a difference for us today obviously, because of his goals, but he was sharp.
"I think in the first half he was also one of the few who was at his level. So well done to him, good game.
"He's been incredible (in training) actually, every time he was never affected by not playing, always training, always staying on the pitch, always saying 'Ruud let's do more'."
Amad's second goal was particularly brilliant as he won the ball back deep in PAOK territory, drove forward, and bent a lovely 20-yard effort into the left-hand side of the goal, albeit with a slight aid of a deflection.
Van Nistelrooy added: "He made his own goal. Coming inside with the left, getting inside the far post was excellent.
"But I think this is what made the goal, he won his own duel and then took the shot for the goal."
Diallo's impressive display saw him register more shots on target (three) and touches in the opposition box (10) than any other player on the pitch.
He also completed the most successful dribbles (two), while also competing in 16 duels during the contest, the joint-highest for the Red Devils along with Victor Lindelof.
Diallo himself praised the work Van Nistelrooy has done since returning to Old Trafford as part of the backroom staff under previous manager Erik ten Hag in the summer.
"Since he arrived at Manchester United he has been very important for everyone," he said.
Prior to their victory over the Greek side, United were winless in six consecutive European matches (D4, L2), matching their worst stretch since 1980 to 1983.
It means they have still never gone seven without a win in European fixtures, though Diallo believed their triumph against PAOK was just as important as getting his season up and running.
"It's been a long time since we won in Europe. Today we showed why we are one of the best teams. It was important to win today.
"It is important to score every time. This season I have been unlucky, so I am happy to score two today. But the most important thing was to win.
"I like to celebrate with the fans and make people happy."