Nowitzki left the court with head athletic trainer Casey Smith, but the 7-footer, despite a noticeable limp, declared himself good to go in the third quarter.
"We needed him," coach Rick Carlisle said. "It was only a five-point game."
The Mavs then blew the game open in the third quarter with simply Nowitzki's presence on the floor helping to draw the attention of the Grizzlies' defense.
Carlisle gave the team Thursday off before the Philadelphia 76ers are at the American Airlines Center on Friday night. Carlisle said Nowitzki is listed as day-to-day, but it would seem that status is more precaution than anything.