Can we report people in the pregame lobby?

So i just recently was in a lobby where a member of my team's champion was banned. He then decided that he was going to troll and intentionally throw the game. He picked a champion that made no sense and picked bogus summoner spells. Eventually someone dodged. This isn't fair that the person who dodged had to lose LP because of this troll in pregame. I wish there was a way we could do something about this. This has happened several times to me in the past and i'm sure to many others as well.