Best midfielder to bring in?

[miegs3]

I'm moving B.Staker out this week to get Rockliff into forward line (which I need to decide on who to bench but thats a different poll).
$300,000 remaining cap but will also move D.Simpson for B.Grundy to clear up another $200,000 so the price shouldn't really factor as I've got enough cash on all benches for cover.

Midfield lineup is currently:
Swan, Ablett, Pendlebury, Barlow, Montagna, Cotchin, __???___, T.Mitchell (Crouch, Arnot)

I'm leaning towards either Jelwood (smashing it lately) or Jack (cheaper) with low break evens so if the others look better the move doesn't cost me anything.

Cheers for help.