LeBron James expressed sadness at Kobe Bryant's retirement decision on Tuesday, voicing regret that he never got to face off against his boyhood idol in an NBA Finals series.

Speaking two days after Bryant announced he would quit basketball at the end of this season, James told reporters he was sorry to see the 37-year-old Lakers star leaving.

“It was kind of sad actually,” Cleveland Cavaliers superstar James said. “The guy's had a hell of a career.”

James revealed Bryant had influenced him at every stage of his basketball career, from being someone he had revered as a schoolboy as well as an opponent and USA Olympic team-mate who had set the standards to aspire to.

Regret not playing against Kobe in the finals: James

But James said it still nagged at him that he had never managed to face Bryant and the Lakers in the NBA Finals. Either Bryant or James has appeared in every finals since 2007, but the two men never met.

“I didn't hold up my end of the bargain in 2009 for the fans, for us, to meet in the Finals,” James said, referring to the 2009 campaign when the Cavs had a 66-16 record but were upset by the Orlando Magic in the Eastern Conference finals. The Lakers went on to eventually win the title.

“I know the world wanted to see it. I wanted it, we wanted it. He held up his end and I didn't hold up my end, and I hate that. I hate that that didn't happen.

“I've seen the stat that since '07 either he has or I've been in the Finals but we've never matched up. And that definitely sucks. Not only for us two being competitors, wanting to go against each other in the Finals, but also for the fans.”

James and Kobe won the gold medal at the 2008 and 2012 Olympics

James meanwhile said he had reveled in being a team-mate of Bryant on the gold medal-winning US Olympic teams in 2008 and 2012, saying he had gained an insight into Bryant's competitive make-up when he saw how he played against Spain's Pau Gasol, then a team-mate on the Lakers.

“The first play of the game he ran through the chest of Pau Gasol and got a flagrant. And Pau Gasol was his teammate with the Lakers. I was like, 'Yeah, this guy is on another level.' It was one of the first plays of the game. I was like, 'This guy's all about winning and whoever he's playing for or who he's playing with at that point in time.' ...It was crazy.”

I knew I had to be better because of Kobe: James

James added that Bryant's ferocious professionalism had also served to motivate him during his NBA career.

“I knew I had to be better because of Kobe Bryant,” James said.

“I knew he was in the gym and I knew he was working on his game. So every day that I didn't want to work out or every day I felt like I couldn't give more, I always thought of Kobe.

“Because I knew that he was getting better and I was like, 'Man, if you take a day off, he's going to take advantage of it. You cannot take a day off.'“