Gasol suffered the non-contact injury during Memphis' 102-86 home loss to San Antonio on Friday night.
With San Antonio leading 28-23 early in the second quarter, Gasol set up to play low-post defense against Jeff Ayres. Although the two players jostled, Gasol did not sustain a blow to his left knee, but he did come up limping and clutching his leg after he appeared to tweak it as he moved forward into defensive position.
The Grizzlies announced during the game that Gasol had suffered a left knee sprain. The Spaniard departed with two points (on 1-for-3 shooting), two rebounds and three assists in 10 minutes.
While it's unclear exactly how long Gasol will be sidelined, this is likely a matter of weeks rather than days. For comparison's sake, then-Hornets forward Carl Landry suffered a Grade 2 MCL sprain in February 2012 and was sidelined for more than a month. Grizzlies forward Quincy Pondexter suffered the same injury in December 2012 and was out for a little more than a month. Thunder center Kendrick Perkins suffered an MCL sprain in February 2011 and was sidelined for roughly three weeks.
First-year Memphis coach Dave Joerger has no means of truly replacing Gasol, who is regarded as one of the best two-way big men in the NBA. Reserve center Kosta Koufos, who was acquired from the Nuggets in an offseason trade, will move into the starting lineup, and reserve forward Ed Davis should see his role increase.
Gasol, 28, was the Defensive Player of the Year last season, when he also made the All-NBA second team and All-Defensive second team. He is averaging 16 points, 7.1 rebounds, 4.3 assists and 1.1 block per game this season.