Vegas coach Gerard Gallant said after the game he had no update on the goalie, who exited with the Golden Knights ahead 3-0.
Fleury, who missed 25 games earlier this season with a concussion, was replaced by Malcolm Subban to start the second period.
Fleury is 27-11-3 for the surprising Golden Knights, who are second in the Western Conference with 99 points in their inaugural season.
He entered Tuesday's action second in the NHL in goals-against average at 2.20 and tied for third in save percentage at .929.
Fleury, 33, was Vegas' first pick in the expansion draft, after spending the first 13 seasons of his career with the Pittsburgh Penguins.
Despite his early departure, Fleury -- who stopped all seven first-period shots he faced -- earned his 402nd career win to pass Chris Osgood (401) for sole possession of 12th place on the NHL's all-time list.