X-rays were negative. Coach Rick Carlisle said he wasn't certain about a timetable for Marion's return.
"We'll hope he feels better tomorrow or the next day," said Carlisle, whose team faces the San Antonio Spurs on Wednesday night, the second in a stretch of four games in five days. "We'll see."
Marion, who was wearing a sling as he left the American Airlines Center, was not available for comment.
The injury occurred late in the second quarter when Marion crashed to the floor after getting his feet tangled up with Los Angeles' Pau Gasol and Mavs teammate Dirk Nowitzki while playing defense. He stayed down for about a minute and was escorted to the locker room by an athletic trainer immediately after getting to his feet and did not return to the game.
"He took a hard fall," Nowitzki said. "We're kind of glad nothing serious happened. He didn't break anything, as I heard, so that's good news. Hopefully, he'll be back soon."
Marion, a 15-year veteran and Dallas' best defender, is averaging 11.3 points and 7.2 rebounds per game this season.
Wayne Ellington, who has played sparingly this season, replaced Marion in the lineup at the beginning of the second half. Second-year forward Jae Crowder also will likely play more minutes while Marion is sidelined.