As for utility infielder, the more I watch Pena playing, the more I think he is an ideal choice.
First of all, he plays great defense at every infield position and he certainly has played better than Ransom. Secondly, he runs fast enough to be pinch runner. Thirdly, he has put together decent at bats so far. I think he is able to execute bunts well. I understand he may not able to hit much, but it may not be matter if we can find another decent bat off bench to play 1B/3B.
Of course, we want to see him getting playing time at AAA. However, Jeter is getting old. No matter he likes it or not, he gets to a point Girardi needs to give him more breaks in order to keep him fresh in my opinion. On top of that, Girardi can't play Cano at 2B every day too.
At the rest of games before A-Rod comes back, I will let Ransom and Pena split the time and give both enough playing time to prove who can be utility infielder once A-Rod comes back.