So which tall forward should come out instead of Post? - Grittiths, Vickery, Riewoldt? Or are you thinking of a tall back he should replace? He has been disappointing at each end this season and the only player I would consider dropping for him would be Thursfield but Post is no tall shutdown defender by any stretch. Playing Post in the season side for experience alone is a luxury at present until he can earn his spot like people are calling for.
Similarly, as an inside ball winner who would Tuck replace - Foley, Cotchin or Martin? Should be play him down back as midsized backman replacing one of Deledio, Newman, Houli, Grigg, Conca, Batchelor or Helbig? Perhaps he could take the offensive place of King, Nahas or White.
I just believe before we start critise the coaches for selection we need to look beyond individual form and look at the bigger picture - structure, roles, game plan, development. Post potentially has a role to play if he can push one of the taller players out but Tuck hasn't the desposal or decision-making skills to warrant selction unless it is through necessity (injury, suspension etc).