The match in Boston will start at 2:30 p.m. on Thursday Latvian time.
Porzingis has been diagnosed with inflammation of his right knee.
Also, it is not yet clear about the participation of Jrue Holiday and Derrick White in the game against the Spurs. Holliday has an elbow injury while White is concerned about his ankle.
This season, Porzingis scored an average of 19.1 points, 6.8 rebounds, two assists and blocked 1.8 shots in 30 matches in 30 minutes.
With 31 wins in 40 games, the Celtics are in first place in the Eastern Conference and in the entire league.
