Here's what they say in the manga - just so people can compare:

Kisame: "You can fight how and where you want, but I don't know... the time is wrong."

Itachi: "Ah. To meet those two and kill them. It's a good place to fight. So they can't increase the number of people they have."

K: "It was good that we found him at the Ramen shop. But he's protected by one of the 3 legendary ninjas. That guy might be a match for the #1 of the Leaf and one of the Mist's Seven Strongest."

I: "Ah, but, it is said that every strong man has a weak point."

So, Kisame said that Jiraiya might possibly be a match for them. This is in contrast to the anime, where Itachi said Jiraiya would beat them. So we have to ask, which is a more reliable source: the manga or the anime?

We can't really discuss it further without spoiling though, so we'll have to wait untill a few more eps are released.