I believe it will hurt quite a bit, if the worst is true. Brady trusts Edelman more than anyone on that team . He's a sure handed, high volume pass catcher. On 3rd downs when the Pats absolutely, positively need to convert, Brady is going to Edelman.
I don't think Amendola has enough left in the tank to replace him. Cooks is a good receiver but until I see it, I don't think theres any guarantees Brady is going to connect with him.