Thomas traded to Los Angeles from the Cavaliers in February.
Thomas will be a free agent in the summer and could leave the Los Angeles Lakers.
Thomas was benched for the entire fourth quarter.
His absence is a problem the struggling Cavaliers don't need.
Cleveland has lost eight of its past ten games.
Cleveland has lost eight of its last ten games.
Did the Cavaliers try to shop Irving before he asked for a trade?
Boston says Thomas can't play back-to-back games right now.
The point guard had 17 points in 19 minutes.
The point guard has recovered from a hip injury.
This is good news for Cleveland.
Thomas is making progress towards a return.
The new Celtics point guard says he was "craving" a coach like Brad Stevens.
The 32-year-old Cleveland star held his annual holiday party on Monday night.
Irving is still learning the offense in Boston.
The season opener in Cleveland is a mouthwatering clash involving the protagonists of the biggest trade of the summer.
Knicks apparently have the next Kyrie Irving in their ranks.
The point guard was part of the deal that saw Kyrie Irving trade to Boston, and Thomas go to the Cavaliers.
The Brooklyn Nets had the NBA's worst record last season.
Irving was careful not to say too much.
The three-time MVP can opt out of his contract in Cleveland next summer, but will he choose to do it then?
The point guard left Boston for Cleveland in Celtics trade for Kyrie Irving.