The 18-year-old, who has consistently dazzled in the youth ranks, was included on the senior team bench for the first time.
But Mourinho, even with Man United notably struggling to break Juventus down, refused to bring Chong – or anyone from the bench – into the game, noting afterwards that he did not have any viable options to choose from.
“Alexis Sanchez was in the stand,” he said. “Lingard was in the stand, Fellaini, may or may not be in the stands, he might have been at home, I did not see him.”
“The only attacking option I had on the bench was an 18-year-old lad who I had never played in the first-team before. And I didn’t think, given the dynamic of the game, that it would have been appropriate to have put him on.”
Writing in a column for the Times, Cascarino criticised Mourinho for refusing to consider bringing the youngster on.
United were in a rut in that second half against Juventus, attacking but not attacking meaningfully, slowly losing energy and confidence.
The response of a manager in this situation is to bring on fresh legs, to try something different. Literally anything. At the time, it was hard to imagine how bringing on Chong for any of the front three would have made United’s performance worse.
But Mourinho, inherently distrustful of taking risks, chose to accept the situation instead and allow the players who started the game to hang out to dry. It was the hallmark of a manager who lacks belief in his players.