Kopitar was hit in the foot by a deflected puck during the Kings' shootout loss at the Minnesota Wild on Monday.
He is beginning his 20th and final season in an NHL career spent entirely with the Kings. The Slovenian center announced his impending retirement last month at the start of training camp.
The two-time Stanley Cup champion has twice won the Selke Trophy as the NHL's top defensive forward. He is the second-leading scorer in Kings history and a five-time All-Star.
The Kings are off to a rough start to the season, losing three straight to fall to 1-3-1. New general manager Ken Holland made only a few changes to the roster that matched the franchise records for points and victories last season.