Solid 20th camp guy. It wasn't going to be another prospect, as they already had five guys battling for the last spot and only four Toros spots to give to the losers. Provided he is signed (and that's not guaranteed), the rotation would look like this:
Parker, Mills, Laprovitolla, Arcidiacono
Green, Ginobili, Murray, Forbes
Leonard, Anderson, Simmons, Garino
Aldridge, Lee, Bertans, LJC
Gasol, Dedmon, Ayres, Richards
With the guys in italics being my guess for the cuts and the bolded players going to Austin. Obvious thing is that the Spurs would be projecting Anderson as a wing for camp, though with the cuts, he'd very much be in the running for combo-forward for the regular season. Still, if Pop is planning on Lee being in the regular rotation, having a camp roster that enforces Kyle being a three is a good thing.
It's also very possible that Ayres is just one of the vets the Spurs bring in to compete for that last spot. Could see a couple of other scrap-heap bigs vying to be this year's Rasual Butler.