Napheesa Collier sat out the fourth quarter of the Minnesota Lynx's 111-58 rout of the host Las Vegas Aces on Saturday with a right ankle injury.
Lynx coach Cheryl Reeve said Collier will undergo testing and imaging over the coming days, but said it was "too early" to have any more information.
"We'll worry until we know more," Reeve said.
Kayla McBride described Collier as being in "good spirits" and was in the locker room with her daughter, Mila, after the game.
The injury occurred with less than a minute to go in the third quarter when Collier collided with teammate Alanna Smith and landed awkwardly on her right foot. Collier remained down for several minutes before getting up and walking off the court under her own power, but with assistance.
She was officially ruled out of the game midway through the fourth quarter.
Collier, who has missed three games this season, finished with 18 points, 5 assists, 3 rebounds and 2 steals in 26 minutes.
Minnesota was up by 43 points when Collier was hurt, but Reeve said she did not regret having her star player in the game at that point.
"I didn't think the game was over," Reeve said. "I don't think like that. She had a sub; she was going to sit out the fourth quarter. Sometimes these things happen."
The Lynx's 53-point win is the second largest in WNBA history and the largest margin of victory on the road ever, surpassing the previous record held by the 1998 Houston Comets.
McBride led Minnesota with 23 points on 8-of-11 shooting -- all of her made field goals were 3-pointers in the first half. She went a perfect 8-for-8 from distance in the first 20 minutes of the game, setting a WNBA record.
"It's a balance, I am excited for the way our team played and the way we showed up today," Reeve said. "And I'm obviously concerned about Napheesa Collier ... I can be both happy for our team and worry. We're hoping for the best."
Added McBride: "It's tough. I thought we put a great 40 minutes together, but you hate to see anybody go down, but especially your MVP."
The Lynx next play in Seattle against the Storm on Tuesday. It's unclear if Collier will travel with the team or will return to Minnesota for the testing.