Well, the middle order has been awful thus far, so having Morgan back will be a huge plus! But who will open? Trott? Bopara? Bell? Prior again? From the last game the 4 non-players where of the 15 where Shahzad, Collingwood, Tremlett and Tredwell. No openers there, so they're going to have to replace Pietersen with someone already in the top 6.
Well, those are the only 4 options, and for my vote it will have to be either Bell or Trott as Priot has been quite poor so far. The loss of Pietesen's off spin might be a problem too. By the way, Morgan makes a handy wicket keeper too.