Boston Celtics star Kyrie Irving revealed he had called LeBron James to apologise for some of his behaviour while with the Cleveland Cavaliers.

The Celtics guard said the circumstances surrounding his Boston team over the last few days have given him a lot of perspective on how he left Cleveland in 2017.

Irving, 26, said he had called James – now with the Los Angeles Lakers – after a loss to the Orlando Magic on Saturday.

"I had to call 'Bron' and I apologised for being that young player that wanted everything at his fingertips," he said on Wednesday. "I wanted everything to be at my threshold, I wanted to be the guy that led us to championships, I wanted to be the leader, I wanted to be all that.

"The responsibility of being the best player in the world and leading the team is something that's not meant for many people. 'Bron' was one of those guys that came to Cleveland and tried to really show us what it's like to win a championship and it was hard for him.

"Sometimes getting the most out of the group is not the easiest thing in the world. Only few are meant for it or chosen for it.

"I felt like the best person to call was 'Bron' because he's been in this situation. He's been there with me. I've been the young guy being the 22-year-old kid, wanting everything right now, coming off an All-Star year … And now I've got to adjust my game to this guy?"

Irving asked to be traded away from the Cavaliers in 2017 and never officially revealed why. But the break was not the cleanest, as Irving reportedly threatened to have surgery rather than play in Cleveland to start the 2017-18 season.

Irving called out Boston's young players on Saturday when he said they do not know what it takes to be a championship-level team.

He apologised to his team-mates during the week.

The Celtics beat the Toronto Raptors 117-108 on Wednesday.