Porzingis, who had missed the previous three games because of a sprained left ankle, complained of the knee soreness midway through the third quarter. The visiting Mavericks announced at the beginning of the fourth quarter that he would not return.
"We'll hope for the best," Mavs coach Rick Carlisle said, noting that Porzingis seemed to be walking fine after the game. "We'll hope that it's not any kind of a serious issue and go from there."
Porzingis, who had 11 points and one rebound in 21 minutes against the Pistons, had surgery in October to address the lateral meniscus injury in his right knee that he suffered during the playoffs, causing him to sit out the final three games of the Mavs' first-round loss to the LA Clippers. He missed the first nine games of the season while recovering from that surgery, and the Mavs have carefully managed his workload throughout the season, sitting him for one game of most back-to-backs.
The 7-foot-3 Porzingis, who entered Thursday averaging 20.4 points and 9.3 rebounds per game, has also had surgery on his left knee. He tore the ACL in that knee in February 2018 in what turned out to be his final game for the New York Knicks.