Lets just say they land Peavy. That would make the current rotation: Peavy, Dickey, Buehrle, Johnson & Rogers. Plug in Stroman/ Nolin in 4 weeks once Rogers is out of innings. That probably puts them 2 weeks (3-4 starts) away from Happ and possibly Morrow returning.
Next year you qualify JJ and take the pick and have Peavy, Dickey, Buehrle, Morrow and one of Rogers, Happ, Hutchison, Stroman, Nolin, Drabek or Romero as the 5th man.