No manager has taken charge of more matches in England than the former Blades boss who was a guest on Matchday Live at the Etihad Stadium.
And after more than four decades as a coach of clubs up and down the country, Warnock says he has never seen such a response to a substitute warming up.
De Bruyne has been out injured for more than four months after having surgery on his hamstring and Warnock says the applause will have meant a lot to the Belgian.
“I’ve never been at a ground where 50,000 people are standing up clapping for a substitute warming up!” he said.
“Kevin will be touched by that and he’ll want to get back and show everybody. What a quality player he is.
“It was a cold day and I’m glad [Pep Guardiola] didn’t bring him on. If he has part of a game next week in the cup [against Huddersfield], it’ll be almost like he’s had a long holiday, which he’s not had for a long time.
“Sometimes players come back refreshed and he’s only got four or five months to play, and he could be flying.”
While De Bruyne will have to wait a little longer to get back onto the pitch, it gave fans more time to enjoy Phil Foden in the middle of the pitch where he has revelled as a creative force.
The 23-year-old claimed assists for both goals against Sheffield United, and Michael Brown who played for both teams, says he is maturing in the role.
“He makes better decisions now,” the former midfielder said. “You love all the flair and the tricks but there were times when he might not have gone into a position to press and left that hole or he might have given it away in a tight situation.
“He just gets it’s now. He’s always had the talent, no one’s ever been more talented than Phil Foden, from the second we saw him in a blue shirt.”
Warnock agrees with his former player and says Foden is improving every season.
“The last time I saw Phil Foden live, he’s matured so much in the last 12 months,” he added. “And he’s going to get even better.”
