Cleveland Cavaliers star Kyrie Irving will join the Boston Celtics in a blockbuster deal that will see Isaiah Thomas head in the opposite direction, US media reported on Tuesday.

Irving has been the subject of contract speculation since it emerged earlier this year that he had requested a trade from Cleveland, whom he helped guide to an NBA Finals crown in 2016.

The 25-year-old will join Boston in exchange for Thomas, forward Jae Crowder, center Ante Zizic and Brooklyn's 2018 first round draft pick.

Irving's request for a move away from Cleveland and LeBron James stunned the NBA when it was confirmed in July.

The Cavaliers have made it to the NBA Finals in each of the last three seasons, beating Golden State once and losing on two other occasions.

The Celtics meanwhile finished first in the Eastern Conference during the regular season but were beaten by Cleveland in five games in the playoffs.

Playmaker Thomas missed the last three games of the series after suffering a hip injury and is reportedly struggling to be fit for the start of the new season in October.

Irving, 25, who averaged 25.2 points on 47.3 percent shooting and 5.8 assists last season, has three years and $60 million remaining on his contract.

Thomas, third in the NBA last season with an average of 28.9 points, will be a free agent after the 2017-18 campaign.

Source: AFP