I don't know. Never been in that situation but I guess It'd depend on how much my SO would spend time with his friend and how close they were to each other.
At the beginning I won't say anything.... because I don't want to look like I want to rule his life.
But certainly, later I won't keep my mouth shut. I'll tell him what I think about his friend and I'll try to convince him why I don't like his friend.
I'm kind of in this situation, myself. I'm not too keen one of my husband's good friends from Uni. but because it's his good friend I make sure I don't allow my feelings to interfere with their friendship.
...Yes, my husband knows exactly how I feel about him but on the same token if he wants to invite him around for the day / evening, I'm always happy to make things work, after all, it's only a day / night that I've got to put up with him and not only that, he lives over 3 hours away from us so to be fair, we don't really see him and his gf all too often.
Why don't you like your bf's good friends?