The point guard was part of the deal that saw Kyrie Irving trade to Boston, and Thomas go to the Cavaliers.
The point guard left Boston for Cleveland in Celtics trade for Kyrie Irving.
Gordon Hayward is a major upgrade at small forward for Boston.
Tanner Ainge, the son of Celtics general manager Danny Ainge, is running for Congress in Utah and had encouraged NBA star Gordon Hayward to stay with the Utah Jazz.
The Celtics come back from a 77-56 third-quarter deficit against the Cavaliers, who are still expected to meet the Warriors in the NBA Finals.
Who cares what the Celtics will do against the Cavs this week? It's all about what they will do with Isaiah Thomas this summer.