Jayson Tatum is back from Achilles surgery, but he could be unavailable Thursday night when the Celtics visit the defending champion Thunder.

Boston listed Tatum as questionable for the game in Oklahoma City for “right Achilles repair reconditioning.” That designation suggests his downgrade is part of a planned reintegration process rather than a setback or new injury.

Tatum, who made his season debut last Friday against Dallas, played 27 minutes in each of the Celtics’ last three games, averaging 19.7 points, 6.7 rebounds and 3.7 assists while shooting 39.3% from the field and 29.0% from 3-point range.

Starting guard Derrick White also is listed as questionable against the Thunder with the right knee contusion he suffered during Tuesday’s 125-116 loss to the San Antonio Spurs. White returned to the game after that injury and finished with a team-high 34 points on 11-of-22 shooting, seven assists, five rebounds and one block, spearheading Boston’s offense after Jaylen Brown was ejected in the second quarter.

Sixth man Payton Pritchard was upgraded to probable after missing the Spurs game with a neck spasm. Center Nikola Vucevic was ruled out again as he recovers from the surgery he underwent last weekend to repair a fractured ring finger.

The procedure is expected to sideline Vucevic, who had been coming off the bench behind starter Neemias Queta, for at least three weeks.

Thursday’s game will be the first meeting this season between the Thunder and Celtics, who rank first and second in the NBA in net rating, respectively.

OKC, which went 2-0 against Boston last season, owns the best record in the league at 51-15 and features arguably the NBA’s best player in Shai Gilgeous-Alexander, the reigning MVP.