Jadeja's batting is not where it was pre injury. And if you're not going to make Rahane bat in this form, I don't think you're serious about winning a cricket match. Dube might be doing well but his peaks of this year are not a patch on Jinks.
Jadeja's bowling has seen a major revival in this season, but his batting has gotten below average. He bats now like a classical ODI batsman who struggles to get the big hits going. Even in the last game vs RR, he didn't make a serious attempt to limit the NRR damage. Added to it, Dhoni's injury woes is forcing CSK to send Jadeja ahead (even a fully fit Dhoni doesnt back himself in his last days, to come ahead of Jaddu). And what Jadeja does is, he ensures that another left arm spinner in the XI is a luxury and indirectly forces Dhoni to not play Santner.