Haywood had missed the past two games with lower-back stiffness.
The last time Haywood played, he scored four points in 13 minutes in a loss to the Los Angeles Lakers on March 12.
This was just the second time Haywood played against the Spurs this season -- he had six points and four rebounds in a loss to San Antonio on Jan. 14. He was suspended for the first game in November and didn't play in the late December contest.
Also, forward Peja Stojakovic, who hasn't played since March 7 because of a stiff neck, missed his sixth consecutive game.
Calvin Watkins covers the Mavericks for ESPNDallas.com.