Lakers forward Pau Gasol left the team's 131-96 win over the Mavericks on Sunday night with a left hamstring strain.
He missed the first 11 games of the season with a right hamstring strain.
"Anytime Pau has an injury, we're very concerned," Lakers coach Phil Jackson said. "He complained before the game started he was feeling some tightness."
A team spokesman said Sunday night that Gasol would undergo an ultrasound test on Monday.