I like his game. I don't think he has incredibly high upside, but he defends pretty well, he has a big shot, and he skates well.
I'd say he's a late second round prospect for now. Could move up some with a good season. I don't think the 2019 US Defensemen crop is all that good, particularly from the NTDP. I have York and Thrun as 21-31 range right now. McCarthy and Warren are probably late 2nd's for now. I don't consider Vlasic as an early round prospect. He has the same problems that Adam Samuelsson had from this past draft, a player who didn't even get drafted. He's a bad skater, and you'd expect him to be a lot better defensively than he actually is.
I actually think the best American D prospect in the 2019 draft might end up being Brinkman who wasn't part of the NTDP program. He was the third American D to make my initial list for next season. I think I heard he's enrolling at Minnesota this year. I wouldn't be shocked if he has a very good season, and gets his way into the top 20 of next years draft.