Who to upgrade??

[bombers481]

My Midfeild looks like this:
Ablett, Barlow, Selwood, Trengove, Ball, Bastinac
Emg: Martin, Mitchell.
and i have 17 trades left.

I have 300k to upgrade someone in my midfeild or else i will cop a 0. Should i trade Bastinac to Pendlebry. Or should I trade Mitchell to anyone ( I am thinking Pendlebry or Judd).
I could also upgrade Ball to to anyone.
Who should i trade??

[ELLsendon]

Ball to Pendle.

Basti will rise as Ball will drop

[bombers481]

Then i will still cop a 0.

[bombers481]

Ill trade Mitchell because i dont want to trade Martin or Ablett.