Antonio Conte took off Alvaro Morata just after 70 minutes in the 2-1 win away at Burnley.
Conte started with two strikers, Olivier Giroud and Morata, and when it was time to take one off, he opted to take off Morata.
The Spaniard missed three scoring opportunities, and Conte believes his missed chances were the reason for the striker’s frustration.
Morata couldn’t hide his anger as he was taken off, and had to be comforted by fellow Spaniard, Cesc Fabregas.
Conte said: “Alvaro must be angry because when you have a chance to score, you have to score, especially for a striker.
“A lot of the time scoring changes your confidence. I think he was very angry with himself for this chance he missed, but I have to look at his whole performance and I am very happy even if he didn’t score.”