Gasol had been on IL since Jan. 25
Gasol, the Grizzlies' leading scorer and rebounder, was put on the injured list Jan. 25 with an injured left foot and missed 23 games. He was on the floor as the Grizzlies began warming up to play Phoenix.
Gasol was averaging 18.9 points and 8.2 rebounds in 33 minutes.
To make room for Gasol, Memphis put Ryan Humphrey on the injured list with a strained left groin. Humphrey is averaging 2.9 points and 2.5 rebounds in nine minutes.
Denver Nuggets: The Nuggets activated forward Nene and placed Mark Pope on the injured list because of a strained left hamstring.
Nene has missed the last 13 games because of a sprained left knee. He is averaging 9.6 points and 5.9 rebounds in 37 games this season.
Jackson was originally signed to the first of two 10-day contracts on Feb. 28.
He's averaging 1.8 points and 1.3 rebounds in four games this season.
MORE NBA HEADLINES
- Lakers predict 'dominant' Kobe in his return
- Sources: Rockets rev up Asik trade efforts
- Nuggets' Robinson fined $25K for comments
- Heat talk trade with Wade out, sources say