Gerald Wallace leaves with back tightness

PORTLAND, Ore. -- The Blazers received some bad news midway through the second quarter as forward Gerald Wallace is being treated for lower back tightness. His return, according to the Blazers, is to be determined.

Wallace got off to a hot start with 13 points in the first quarter.

Portland led the Mavericks 31-19, but has since fallen behind 41-37 with 4:16 to go in the first half.