Shortly after making a save with his right arm that knocked the stick out of his hand, Lehtonen skated to the Stars' bench with 6:11 remaining, tried to stretch, but left the game. Lehtonen, who entered the game with a .933 save percentage, took an earlier shot off his mask during a busy opening 13 minutes.
Lehtonen has been plagued by groin injuries throughout his career and missed time with the problem last season.
"He's going to be re-evaluated when we get back to Dallas," coach Glen Gulutzan said. "It's a lower-body injury ... To me, it doesn't seem as severe (as last season's injury)."
Lehtonen was replaced by Richard Bachman, who gave up six goals in a 7-4 loss at the Calgary Flames on Wednesday. Bachman allowed three goals but stopped the last 15 shots he faced as the Stars rallied for a 4-3 victory.
He's ready if Lehtonen can't play at home against the Flames on Sunday.
"The good news is he got up quick and he got up under his own power, so that's a good sign always as a goalie when you can do that," Bachman said. "But if they need me, I will be there."
The injury continued a run of bad luck for Lehtonen in Vancouver. He entered 0-3-0 there with a 5.19 goals-against average.