Holtby, who has started 37 consecutive Stanley Cup Playoff games for the Capitals and 59 of their past 60 postseason games dating to the start of the 2012 playoffs, said he'll do his best to support Grubauer and be ready to play if needed.
"My job is just to focus on my game, getting it the best it can get to," Holtby said. "Coach's decision who plays or not doesn't have anything to do with me. I'll just focus one practice at a time, trying to be a positive influence around the team, and go from there."
Grubauer made his lone Stanley Cup Playoff start in Game 2 of the 2015 Eastern Conference First Round against the New York Islanders. Filling in for an ill Holtby, he made 18 saves in a 4-3 victory.
"It was a long time ago," Grubauer said. "[It's the] same thing, same mentally. Every puck in the season, every situation matters. This game is important, yeah, but so is the regular season. Every goal you let in and every goal we score is important. So just go in with the same mindset as Game 81 or 82. You prepare the same way if you play or don't play."
Holtby, 28, was 34-16-4 this season, but his 2.99 GAA and .907 save percentage are the worst of his eight NHL seasons. In 59 playoff starts, Holtby is 29-30 with a 2.00 GAA, .932 save percentage and four shutouts.
The door opened for Grubauer to take over the starting job following a rough eight-start stretch from Feb. 11-March 6, when Holtby went 1-5-2 with a 4.82 GAA and .854 save percentage and was pulled three times.
Grubauer started four straight games after that to give Holtby time to work in practice and reset mentally. Since then, Holtby is 5-1-0 with a 2.67 GAA and .911 save percentage, but Grubauer played the more important games, including a 3-1 win against the Pittsburgh Penguins on April 1 that clinched first place in the Metropolitan Division.
"We just took everything -- the whole year, numbers, all of that stuff," Trotz said. "We just talked about it, and as I said, with two goaltenders, you have to make a decision. We're going to make that decision and run with it. We'll just worry about Game 1."
Grubauer's only other NHL playoff experience came in relief of Holtby in a 6-2 loss to the Pittsburgh Penguins in Game 2 of the Eastern Conference Second Round last season. He played one period, allowing two goals on nine shots.
Grubauer also has playoff experience with Hershey of the American Hockey League in 2013 and 2015, and was the No. 1 goaltender for Windsor of the Ontario Hockey League, which won the Memorial Cup in 2010. He was 16-2 with a 2.69 GAA and .909 SV% in 18 playoff games that season.
"[Grubauer] has been a No. 1 goaltender," Trotz said. "He's won a championship as well. This is part of the evolution of a young man who keeps growing as well, just as Braden has when he was in that position a few years back. As I say, we're pretty blessed to have two pretty good goaltenders right now."