Pep Guardiola hopes anger at missing out can fuel more sensational performances like that of Jeremy Doku at the weekend.
Guardiola said: “I want Jack angry and I want him to play good, and then Doku – be angry that he hasn’t played the last two games. This is the way to maintain the consistency at that level.”
Grealish has had a frustrating start to the season after missing a month due to a dead leg, but Guardiola has no doubt he will get back to his best.
“Jack is back,” he said. “The way he played at Old Trafford, to give us more composure and more powers in that position, it was decisive for us.
“We need everyone. There are a lot of games and everyone has to compete.
“As much as Jeremy and Jack perform, and I can play both at the same time, but when they don’t, train better the next day because the moment is coming, and when you are mentally there in the head you will perform well.
“Then we will win games and you will be happy and everyone will be happy. This is what we have to do.”
City will check on the fitness of star striker Erling Haaland ahead of Tuesday’s Champions League clash against Young Boys. The Norwegian was removed at half-time on Saturday after twisting his ankle.
Guardiola was pleased his side managed to score six without any contribution from the prolific Haaland but admits he wants him back as soon as possible.
“I know Mateo (Kovacic) is not a goalscorer, but we have now more players involved, with and without Erling – but I want Erling on the pitch.”
Holders City cans secure their place in the Champions League knockout stages for an 11th successive year with victory over the Swiss side this week.
Guardiola said: “It’s so important, more than you can imagine, because we can park the car until February and focus on the Premier League and others. We have to close it on Tuesday.”