Per David Schoen of the Las Vegas Review-Journal, DeBoer told reporter on Friday that he expects Lehner to practise on Saturday and be in uniform on Sunday when the Golden Knights host the San Jose Sharks.
DeBoer's comments came less than an hour after ESPN reported Lehner would be going under the knife and ending his season.
Lehner recently returned from a knee injury. ESPN speculated that the season-ending surgery is on his knee.
Lehner played five games after returning on April 3 from what the team termed a "lower-body injury."
Although Lehner struggled with an .889 save percentage in five appearances since his return, backup Logan Thompson has won seven of his past 10 decisions, with a save percentage of .922.
Lehner's play was criticized by DeBoer, and he was pulled after the first period of Wednesday's overtime win over the Washington Capitals after stopping 12 of 13 shots.
The Golden Knights are two points behind the Dallas Stars in the race for the final wild-card playoff spot in the Western Conference.