Reports had suggested Thomas could feature against the Boston Celtics on Wednesday, but he will instead come off the bench under a strict minutes restriction in Portland.
Thomas - who was traded to the Cavs from the Celtics in August - has missed the first 36 games of the season rehabbing a hip injury suffered in the post-season.
Coach Tyronn Lue is relishing having his new star available, and believes it will significantly strengthen the Cavs.
— Cleveland Cavaliers (@cavs) January 1, 2018
Lue said: "It's great [to have him back] because I think we've all been like 'is it going to happen? When is it going to happen?' Now its finally here.
"Just seeing how he can play with pace, his speed and quickness and ability to shoot the basketball, it really changes our team. I'm just really excited, it's a good moment for us."
Thomas is also looking forward to his first outing, and has vowed to play his natural game when he eventually turns out for his new side.
"I'm a scoring guard so I know how to put the ball in the basket. They traded for me for a reason, and I will just play the game the way I know how to play it," said the 28-year-old.
"And that is to make plays, try to make the right play each and every time.
"Those guys have welcomed me with open arms, they've always said 'stop passing, be you, be aggressive and look to score' and that always makes you feel comfortable that they want me to be who I am. That's all I can be."
Photo Getty Images. Caption: Isaiah Thomas