Kyrie Irving is the "most gifted player the NBA has ever seen" and holds the key to the Dallas Mavericks' chances of victory in the NBA Finals, according to former team-mate LeBron James.

James and Irving played together with the Cleveland Cavaliers from 2014 to 2017, making the NBA Finals in each of those seasons and triumphing in 2015-16.

Irving then enjoyed stints with the Boston Celtics and Brooklyn Nets before joining Dallas last February.

He has been in great form during the offseason, averaging 22.8 points and 5.2 assists as well as shooting 48.5 per cent from the field to help put Dallas in contention for their second NBA championship.

Speaking on an episode of his 'Mind the Game' podcast, James said of Irving: "I'm so happy and so proud to watch him continue his growth.

"I'm so f****** mad at the same time that I'm not his running mate any more.

"I would call Kyrie 'the wizard' all the time. There was nothing on a basketball floor that Kyrie couldn't do."

James highlighted Irving's performance in Game 1 of the Western Conference finals, when he scored 24 of his 30 points in the first half against the Minnesota Timberwolves, as the standout moment of this postseason.

While Boston may be favourites for the NBA Finals, which tip off on Thursday at TD Garden, James says Irving's ability gives Dallas a chance.

"That was like, 'oh s***, Dallas may be able to not only win the Western Conference finals, they might be able to win the whole thing'," James said of Irving's Game 1 display.

"Because of that wild card. He's the most gifted player the NBA has ever seen."