Fact is, you're required to dress two goalies to play the game. If you don't, you must forfeit (I'm pretty sure that's the rule). And to play in a game, you have to be a student with NCAA eligibility remaining.
So that would mean if we only had JPL and Walski, and one of them got hurt, they would still both have to dress and risk having to play hurt.
I think we'd be better off having a student as a third/practice goalie who could at least fill the net during a game if they had to. It would be rough on the defense, but it would keep us from having to forfeit the game.
All that being said, I very much doubt Hakstol would pick up another goalie would wouldn't be eligible to play in a game if necessary.