All-Star guard Russell Westbrook and the Oklahoma City Thunder have reached agreement in principle on a new three-year contract worth $85.7 million, league sources told ESPN.

Westbrook, 27, will sign the contract on Thursday in Oklahoma City, sources said.

Talks between the sides centered around the addition of two more years to Westbrook's current deal, which expires after the 2016-17 season. The new deal calls for an $8.7 million increase in Westbrook's salary for this season, from $17.8 million to the maximum $26.5 million. He would then earn the max the next two seasons.

Only one of those seasons is guaranteed, though.

Westbrook, who has played all eight seasons of his career in Oklahoma City, will have a player option for the third season of the deal that would allow him to capitalize on the league rule allowing players who have completed 10 seasons to earn a larger max salary.

Read more at ESPN.com.au