@CaptainKid:
I think that makes more sense than Dofla coming to PH and fighting Luffy there. Then again considering how easily Vergo handled Law who was on par with Smoker, Luffy beating Vergo anytime soon in my mind is doubtful. Vergo will own monster point Chopper and besides Chopper had to be carried to the lab so him using monster point anytime soon is doubtful. I'm hoping for a Zoro vs. Vergo fight, which will depend on Zoro getting to the lab before Franky wakes up.
Vergo had the advantage of… "something" happening to Law as he was approaching him, reducing him to a pained wreck and slowing his reaction enough to let him wallop Law repeatedly without repercussions. If it is CoC, then that implies a lot about the difference in strength between them, and is essentially an impassable barrier. But Law wasn't reacting the way most people do when they are affected by CoC. He wasn't foaming at the mouth and he stayed conscious.
And I really doubt Doflamingo is heading towards an island right near the Red Line from where ever he currently is. If he's in Paradise, then that means he has to go through Fishman Island, in which case he was either trailing Luffy for some time, or it will take him at least four days to get there (three to get a ship coated, one to travel). If he's in the New World, then he's traveling through extremely dangerous seas to... what? Fight some kid that's already been captured? Watch him be killed by his resident mad scientist?
Oh, and having thought it over, Caribou probably does work for Doflamingo. If he worked for a Yonko, he'd probably try to use that as a shield against reprisal from other pirates, but if he was working for an underground broker who valued anonymity, he'd know better than to go spouting off his boss' name. It also fits well
=Edit=
Also, I agree with Luffyspissed. They are better suited to the opposite opponent.