Would Cotto even be ready by September 13th? That in itself has me skeptical as another poster pointed out earlier that it's likely too soon for him to return. It's likely going to be Maidana as nobody else is out there. Swift is moving up, and I doubt fighting Floyd at the weight is a good look for him. He's just not ready. Top Rank fighters aren't even in the picture. Khan will be too weak after wrapping up Ramadan. Thurman isn't lucrative at this time, and he's not well rounded enough just yet to make it as interesting as other fighters int the picture. Maidana is the only logical choice, as they already have a story, and some controversy considering the ignorance of casuals. Granted, I think if they rumble again, it's going to be a rout. The first fight was the bait, the second fight will be the switch. After Maidana is clearly out of the picture, the landscape will be clearer with Porter having established himself, Swift possibly establishing himself, same with Thurman. After that, maybe Cotto will meet Floyd halfway, or Khan will get the nod after a tune up fight or not, the latter of which would benefit Floyd as a rusty Khan benefits Floyd. Lets keep it reality, Khan might have a suspect jaw, but Floyd's brittle hands ain't knocking anybody out, and Khan's speed will give Floyd trouble.
Have to say, out of all those scenarios, the most dangerous one is Porter. If Porter smashes Brook, which I think he will, it might not be a good idea for Floyd to rumble him if he's still focused on remaining undefeated. He said in an interview that being undefeated isn't as serious to him as some make it out to be. I think when he said that, it was a rare moment of honesty on his part as he acknowledged that at this point in his career he's vulnerable. Porter would be the best candidate to dethrone him. If you think Maidana gave him problems, well, Porter actually pulls off what Maidana only attempted.