Who is Sergio Martinez's biggest threat if he chooses to fight @154 again?

Miguel Cotto. He's the only one I consider elite at this point that would fight Martinez. Floyd and Manny will avoid him like the plague, and they should, because his size advantage would be too much and I don't think it would be fair. Chavez Jr has fought only tomato cans. Alvarez is untested and isn't seasoned enough. Martirosyan I haven't been impressed, and I don't feel he has the power to keep Martinez off, and P-Will, I highly doubt would step back in the ring with him. Cotto's got good technical skill, he can brawl, he very good power and he has Emanual Steward in his corner. I know a lot of people think that Martinez would crush Cotto, but I happen to think that Cotto would put up a great fight and possibly upset the bigger Martinez.