Dude would not make it to the PS. Cutting him, if it happens, will end up being one of Fisher's biggest mistakes.
But I doubt it will happen. Dude made the team with those clutch catches and cemented what they'd seen to date all through OTAs and camp.
I'm going to say he's significantly better than 50-50 right now to make the final 53, even if he loses two full weeks at this point. Every time I've read something about Spruce in camp, the two common threads on him are 1) he knows how get open on a consistent basis, and 2) he catches everything thrown to him. If others are seeing that, Fisher, Groh and Boras are seeing it too. And now, 89000+ fans in the Coliseum have seen it, as has a TV audience watching the game. It's pretty clear he can play, and it's also pretty clear that of the rookie WR's the Rams have brought, he far and away stands out above the others.
Despite this setback, I think he makes it. And further, I think he sees significant playing time in his rookie year.