A shit load. And he isn't going anywhere.
I am not suggesting he get 1,000 at bats. He spend the rest of this season and the first month or so of next season, he'd maybe get another 450 at bats or so IF (a big if) he stays healthy. He'd still be well shy of 1,000 at bats. Obviously that is not a cut off, and Robert is probably the best CF option in the organization, but rushing him to the big leagues just seems so short sighted. Just let him excel his way up the minor league system. WTF is the rush?