Chelsea manager Thomas Tuchel has praised Callum Hudson-Odoi's reaction after he was substituted after only playing 31 minutes of the 1-1 draw with Southampton on Saturday.
The 21-year-old winger came on at half-time but was replaced after 76 minutes and Tuchel said he was not happy with the player's "attitude and energy".
"We decided to speak to him in front of the group," added Tuchel on Monday. "We got the only reaction we wanted - he went back to normal mood, smiling and had a very good training."
Chelsea play La Liga leaders Atletico Madrid in the first leg of their last-16 Champions League tie on Tuesday, although the match will be held in Bucharest, Romania because of coronavirus restrictions.
The German said Hudson-Odoi could feature and it is understood the player regards the substitution as part of his learning process and has no ill feelings.
Prior to the match at Southampton, Tuchel handed the England international four starts in his five Premier League games in charge after replacing Frank Lampard as manager.
Tuchel said of the decision: "It's not a big thing at all. I've spoken to Callum and to the whole group. Sometimes these things happen in football and it was my decision.
"Maybe I was being harsh because he was on my side of the pitch, but I didn't feel he was into the game.
"Callum's been fantastic for me and it's on him to show me that every game and every day in training.
"He has taken a hard decision. Now he must swallow it and come into training ready to work ahead of Atletico, a game which he has every chance of starting."
Club captain Cesar Azpilicueta believes Hudson-Odoi would learn from the experience. He said: "It's not nice to come on and then be brought off after 30 minutes.
"What's important is to see his reaction, a positive reaction. He will get better and stronger.
"When you face this situation, the important thing is the reaction. The next day in training he talked it through, that's it, Callum is a strong boy, I'm sure he will get better and he is very important for us."