According to David Thorpe's rankings (Insider) the 20th best rookie in summer league was the second overall pick, Evan Turner:
Turner was, at best, a poor player in Orlando compared to any reasonable expectation -- not locked in, bad body language and poor skills.
But don't get too alarmed. It's a testament to his talent that he still made plays on the glass and had some good offensive moments. I suspect that while almost every other player spent three to eight weeks before July working on their games and working out for teams, Turner did little on-court stuff. No doubt he'll look better in preseason and beyond.