Per the Grizzlies' communications department on Twitter, Gasol is officially listed as day-to-day after his X-rays were negative.
Ronald Tillery of the Commercial Appeal noted Gasol was limping "pretty badly" around the locker room and that Grizzlies head coach David Fizdale said the severity of his injury is unknown.
Gasol told Tillery his ankle is "not broken. That's good. It just hurts."
Injuries have been a problem for Gasol lately, though this is his first issue this season. The Spanish star was limited to only 52 games last season, the second time in three years he failed to reach 60 games.
The foot injury that ended his year in 2015-16 also kept him out of the Summer Olympics in Rio de Janeiro in August.
Gasol suffered a bone bruise during the preseason before working his way back to the lineup in time for the regular season.
When healthy, the 31-year-old player is one of the top big men in the NBA. The two-time All-Star was named first-team All-NBA in the 2014-15 season while averaging 17.4 points per game to go with his 7.8 rebounds and 1.6 blocks per game.
He has been as good as ever offensively in 2016-17, adding an outside shot while being more aggressive with the ball. He is averaging a career-high 19.5 points to go with his 6.1 rebounds and 1.6 blocks per game so far this season.
Even when he doesn't fill up the stat sheet, Gasol has a reputation of an elite interior defender who makes the entire unit better. He was named the league's Defensive Player of the Year after the 2012-13 season.
With the center under contract through the 2019-20 season at over $20 million per year, the Grizzlies might stay cautious as they focus on the long-term health of one of their franchise cornerstones.
Zach Randolph, JaMychal Green and Jarell Martin will all likely see increased minutes in a frontcourt rotation while Gasol is unavailable.