Sending Rios down is pretty much senseless, and I can't see this taking place, regardless of what the Toronto Sun may report. I can see Gross getting an opportunity to play some, but expect the AB's to come more at the expense of Johnson or Catalanotto. Also, we could see him DH'ing when Hillenbrand takes 3B on days when the constantly nicked up Koskie cannot go. Plus, there's always the possibility that Hinske won't hit, will lose the 1B gig to Hillenbrand, which would put Gross into the DH slot.
In other words, plenty of possibilities, but I think least among them is Rios losing his job.