Marc-Andre Fleury, the team's No. 1 goaltender, stopped 22 of the 23 shots he faced in a 4-1 exhibition victory over the Arizona Coyotes on Thursday.
DeBoer said in July he's "not going to be afraid to play either" netminder in the postseason. Fleury said at the time he was fine with competing for the starting role in the playoffs.
The 35-year-old veteran, who's been Vegas' starter since the club's inception, went 27-16-5 with a .905 save percentage and minus-6.5 goals saved above average in 49 games during the 2019-20 regular season.
Lehner, who turned 29 in July, won all three of his starts after joining the Golden Knights, posting a .940 save percentage in those victories. He went 16-10-5 with a .918 save percentage and 10.17 GSAA in 33 contests with the Chicago Blackhawks before the February trade.
Pacioretty has been rehabbing a minor injury and didn't travel with the team last weekend when it flew to Edmonton to enter the Western Conference bubble. The 31-year-old winger led the Golden Knights with 32 goals and 66 points in 2019-20.