I bet Brett Jackson gets a Sept 1 callup and they see what the kid can do. He's been hitting pretty well lately at Iowa after getting off to a slow start. .292 with 8 homers and 17 RBI in 30 games and a OBP of .382.
I think you'll see Wellington Castillo (.302 15 HR 35 RBI in 55 games) Lou Montanez (was up earlier, is hitting .321) and Bryan LaHair (.335 32 HR 88 RBI in 113 games) all called up too, probably LeMahieu too who was up earlier. Pitching wise, I'm guessing Casey Coleman comes up while Z is out as someone has to go into the rotation and I don't see that being Ortiz. Not sure who else will get callups but Scott Maine and possibly John Guab (came in the DeRosa trade) and the usual Justin Berg but looking at the I-Cubs pitching stats there are a lot of 5+ ERAs on the staff right now so even in AAA the pitching has sucked this season too.
Jackson wont come up. Cubs have a lot of players they need to add to the 40-man roster this off-season to protect them from the rule-5, so if they bring up Jackson, that will be one less prospect they cant protect.