Alright so I wanted to get a little bit more in-depth with this...
If people want to say that Grubauer hasn't been good, that is a statement I can agree with. I was going through some stats over the weekend and didn't realise that his save percentage at this point is .908%. Is that bad? Not even in the slightest, but it isn't great either...it is somewhere in the middle.
I went through all the relevant teams' starting goalers and found this...
(BOS) Tuuka Rask: .927%
(DAL) Ben Bishop: .925%
(WSH) Ilya Samsonov: .923%
(NYI) Thomas Griess: .922%
(BOS) Jaroslav Halak: .920%
(VAN) Jacob Markstrom: .917% (I suggest that he's played much better)
-------------------------------------------------------------
(TBL) Andrei Vasilevsky: .917%
(NYI) Semyon Varlamov: .915%
(STL) Jordan Binnington: .911% (Has had a .879% save over his last 10 games)
(TOR) Frederik Andersen: .910% (Has played at .893% level since Jan 1st, 2020)
(CGY) David Rittch: .910%
(COL) Phillip Grubauer: .908%
(LV) Marc-Andre Fleury: .908%
(PHI) Carter Hart: .905%
(CAR) Petr Mrazek: .904%
(ANA) John Gibson: .904%
(PHI) Brian Elliott: .901%
(PIT) Matt Murray: .900%
(NSH) Pekka Rinne: .898%
(FLA) Sergei Bobrovsky: .897%
(WSH) Braden Holtby: .896% (Has let in 4 goals in 6 out of last 10 starts)
Now if you calculate the high-dangerous scoring chance save percentage, Grubauer is 11th in the entire league after you get rid of some two games played and backup goalers...
1. Rask: .885%
2. Binnington: .865%
3. Merzlikins: .863%
4. Rinne: .862%
5. Bishop: .859%
....
11. Grubauer: .846%
Grubauer is also 12th in the entire league in regards to high-dangerous goals saved above-average after you get rid of some backup goalers and rookies who've played like four games maximum...
1. Binnington: 10.01
2. Rask: 8.64
3. Rinne: 7.57
4. Bishop: 6.62
5. Blackwood: 6.28
....
12. Grubauer: 4.26
Grubauer also faces the 10th most rush attempts against in the league. The goalers who have faced the least are both the Bruin netminders along with the Wild goalers, Carter Hart, and Samsanov in comparison...
1. Andersen: 63
2. Price: 59
3. Fleury: 57
4. Gibson: 56
5. Vasilevskiy: 54
....
10. Grubauer: 43
If there is one thing that Grubs can fix on, it is rebound shots faced as he has faced the 12th most at 95 and in comparsion first place is Bobrovsky at 138, Hellebuyck at 137, and Gibson at 118. Additionally, Avs are currently 23rd in the league when it comes to high-dangerous scoring chances generated, but do have a positive number in regards to high-dangerous chances vs against percentage, which is good enough to be 10th (51.72%). Avs as a team do have the 9th best high-dangerous save percentage as well, which backs up Grubauers numbers. Lastly, Avs have a good team-combine save percentage that is fourth in the league at 92.96% which is only behind the Blue Jackets, Stars, and Bruins.
So if I was going to guess based on the results I dictated in this post, what I think is killing Grubauer and his save percentage is the penalty kill. Now I don't have time to go through the PK numbers, but I'll estimate that Grubauer is probably close to Murray and Rinne's level and numbers once you filter out PK. Some coaches say that your goaler has to be your best PKer, I don't disagree with that, but when you see the eye test there is so much wrong on the PK from a combination perspective. Grubs isn't helping his teammates with his rebound control and number of them, but his teammates aren't doing a good job at anticipating the play, staying stationary, puck watching, and not clearing loose pucks in front of Philipp.
In my conclusion, I still suggest that Grubauer is being negatively targeted by certain selective vision posts. True he hasn't played extremely well to this date and some of his streakiness is definitely real, but I am also under the impression that good teams don't always have to rely on their goalers. Avs have good underlying numbers for the most part, perhaps with a high PDO and shooting percentage, but nothing insanely out there. What Grubauer needs to be for us is what Chris Osgood was for the Detroit Red Wings, someone who can keep momentum on our side with a timely save. For majority of his career he has been that, but I suggest that special teams have exacerbated his numbers and negativity from posters.
TL;DR Version: Grubauer is playing like a top 12 goaler in the NHL, at least on 5v5. Penalty kill he has struggled just like his teammates have.