He was not expected to return.
Gasol, who missed the first 11 games of the season with a right hamstring strain, left the game with 4:48 remaining in the first quarter when he strained his left hamstring in an unrelated injury. A team spokesman said Sunday night that Gasol would undergo an ultrasound test on Monday.
"Anytime Pau has an injury, we're very concerned," Lakers coach Phil Jackson said after the Lakers beat the Mavs. "He complained before the game started he was feeling some tightness."
Gasol made all three of his field goal attempts for six points before leaving after seven minutes.
Gasol was averaging 17.3 points and 12.0 rebounds a game since returning to the starting lineup Nov. 19.
He missed just one regular-season game last season.
Information from The Associated Press was used in this report.