User blog comment:Zhonke/WHO DO YOU THINK WILL BE THE NEXT SH PIRATE??/@comment-3213092-20110504090558/@comment-3242083-20110507124858

The problem with Jinbe is that he has a "captains personality". He is a leader, not a subordinate, at least since the incident with Tiger. He will be considered as one of Luffy's closest allies, but thats it.

On top of that, it would be weird if someone with such power would join the crew (at this point). While the Strawhats had 2 years to improve their skills, a Shichibukai is still a Shichibukai. The gap between him and the other crewmembers (except Luffy) is just too big for the moment.