Jiraiya isn't fast enough
So you're arguing that Danzo, who was inferior to Sarutobi in his old age, is faster than a ninja who was kage-level before going sage mode? Jiraiya is being horrendously underrated here.
He wasn't fast thats why he died
watch killer bee vs sasuke
Have you ever seen jiraiya moving at speed like that?
That's awful logic; so you're basically saying "if he was so fast, how come he's dead?". So because he lost to one of the strongest characters in the show, he's not as fast as Sasuke. Nice.
I have seen Bee vs Sasuke multiple times, I never claimed Jiraiya was as fast as Bee whilst in beast mode. But it would be idiocy to claim that you need to be at least as fast as Bee to keep up with Sasuke (in case you didn't notice, team Taka were gettign their asses handed to them, not just Sasuke).
@GIRUGAMESH: No that's just speculating now. You can't honestly sit there and say that Jiraiya has anything that can go through a complete Susanoo. Yes the only complete Susanoo we have seen was Itachi's but Sasuke with MS and a complete Susanoo would be far too much for Jiraiya. Jiraiya isn't even more powerful than Sage Mode Naruto. He's not going to be able to defeat super-hax Sasuke who has managed to use Susanoo and Amaterasu with very low chakra levels and exhaustion.
Since we have seen no feats from a fully completed Susanoo without the mirror (Itachi's susanoo, that is), it would be speculating to argue that it would be immune to any attack in the first place. Yes, it would provide an awesome defence, and I'm not arguing that any of Jiraiya's attacks are capable on one-shotting it or anything, but they would do enough damage to put huge levels of exhaustion on Sasuke, meaning he could not sustain it for long. When that happens, Jiraiya moves in to take down the weakened Sasuke.
Like I said before, he could also go for the frog song option if all else fails, or summon a swamp underneath it.
Also, yes, Sasuke did manage to use Susanoo with low chakra levels; well, long enough to fire off one arrow anyway, before it died on him and he went blind.