User blog comment:Xilinoc/Ch. 560 - Rages at Ringside/@comment-7079377-20131204201204/@comment-11051098-20131204222954

I always thought he was a fighter, seeing how he attacked Renji when he first appeared.

Except Ichigo, I think Ikkaku is the only one who has a Bankai, and is not a lieutenant or captain.

@ Caress - he said so, yes. I suppose he included SHûhei, Ikkaku and Yumichika there, but he probably doesn't know their ranks, and if they have reiryoku cose to captain-level, perhaps he judged them based on that.