By SABC Sport
30th July 2024
The 28-year-old was named on Gareth Southgate's preliminary list but was left out of the final group which eventually finished runners-up to Spain in Germany earlier this month.
"I'll be honest, it was probably, football-wise, the most difficult thing I've ever had to deal with in terms of my own career," he told a press conference ahead of City's friendly in Florida against Barcelona.
"I was absolutely heartbroken.
"I also had some stuff happening off the field. People from the outside don't see. They think we're just robots. We have a life off the field. Sometimes it's difficult to deal with that.
"If I sit here and say that I don't feel like I should have been in the squad, you're gonna be thinking, 'What's this guy like? What's he thinking?'. So, of course, I thought I should have been in the squad.
"I felt like I offer something different to the players in the England squad, but it is what it is.
"Moving forward, I have to just try to use that as motivation going into this season and try to have the same mentality as I had two years ago.
"My first season at City, I don't think I performed as well as I could. The second, I played a lot of games. I wanted to come back stronger.
"I'm not stupid, I know what it takes for myself to bounce back this season. You know how good a player I am, I need to regain my fitness and form and I know what I can do personally."
City boss Pep Guardiola has no concerns about the winger's attitude.
"No complaints. His body language, behaviour, the way he trains is the Jack we know. He'll be back to his best because we need him," he said.
Meanwhile, Guardiola accepts playmaker Kevin De Bruyne, who is attracting interest from the Saudi Pro League, has earned the right to decide his own future.
The Belgium international has a year left on his contract but the City boss said his length of service to the club â- he joined in 2015 â- meant he was entitled to choose his own destiny.
"What he has done for us is massive so he can decide," Guardiola added. "The information I have now is he will stay.
"The club informed me that they didn't have an offer. I don't know what will happen, but I want him to stay."