I'm not going to say he replaces him because he's not on the same level by any means (nor do I WANT this to happen), but i'm going to laugh in everyone's face when Petro walks this summer, and we have Faulk to fall back on as someone who will step in on the PP and #2RD role as Parayko moves to #1D. I'll put an avatar or $ bet up on this happening.
I will not laugh. I have been pretty vocal that the defense would be in a better spot with Faulk (and his contract) than without if Petro were to walk.
However, I am firmly of the mindset that the Cup window closes if Petro walks. If Petro walks, I think the proper move by the organization would be to sell most the vets for futures/younger guys and try to do a 1-2 year retool to focus on a new core of ROR, Thomas, Kyrou, Sunny, Parayko, and Dunn.
IMO, letting Petro walk and having Faulk as the 2RD and PP guy puts this roster in that horrible spot where you are good enough to make the playoffs but not good enough to actually contend (let's call it the Minnesota middle). If the plan/intention is to let Petro walk over $1-2M a year, then we shouldn't have been locking ourselves into contracts that suggest we are in win-now mode.
The Blues last year and the LA Kings are the only teams in the last decade to win the Cup without a D man who scored at least 44 points in the regular season (Doughty missed that mark in the regular season both years they won). However, Doughty had 16 points in 20 playoff games in 2012 and 18 points in 26 playoff games in 2014. Petro had 41 points in 71 games last year before putting up 19 points in 26 playoff games.
To win a Cup in today's NHL, you need a D man who is outscoring a few of your top 6 forwards. Having a few good but not top end offensive D men doesn't cut it.
Parayko is a great D man, but he is not capable of providing that type of offense. His career high is 35, he had 28 last year and is on pace for 30 this year. More offensive usage isn't getting him into the mid-40s. Faulk hasn't hit 40 points since 2014/15. Increased usage isn't getting him there. Dunn's career high was 35 last year and he is on pace for 24 this year. A sudden jump to 45+ in the next couple years is pretty damn unlikely. If Petro walks, we no longer have that D man in the organization and good luck finding one without giving the same amount of "overpay" it would have taken to keep Petro.
I'm firmly in the camp that is fine with the Faulk/Schenn deals if we keep Petro and keep the window open. If Petro walks, then I absolutely hate giving out 2 "win now at the expense of the future" contracts right before entering what should be a retool.
You can understand that the presence of Faulk makes for a better 2020/21 blue line in the absence of Petro without thinking that the extension to create that reality was a wise decision.