I think that part of the reason for not why he is not up is that if he sucks he can refuse the assignment once DFA'd. If he comes back up we are likely to lose him, and I think the front office sees enough in him to try to keep him longer
I think diving was the wrong choice. Really hard to get the ball. Maybe should have left the bag and gotten in front of the ball and kept it in the infield. Better to have the runner at first.