Hi Shannon! While lumpy potatoes won't ruin your rolls, you will end up having a slightly different texture since those potatoes will not dissolve into the dough. Your final rolls, once baked, will have small pieces of potato in them. Unfortunately, there really is nothing to do at this point since the dough has been proofed. For next time, running the potatoes through a food mill or a sieve can help remove any of those stubborn lumps and you'll end up with a much smoother dough when you add them. 

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