Well, Pedroia played only 6 games and may not ever return to the lineup. Nunez is what he is, a guy slightly above replacement whose versatility is the sole reason he's on the club.
I'm not sure bringing Chavis up is the "gamble" or "panic move" that people are saying it his. He's a guy that can hit in the minors. He's their top prospect and has nothing left to prove down there. His defense may never get better, so there's no issue with just bringing him up and see if he can stick.
To me, a panic move would be bringing up Dalbec, Hernandez or Chatham today. Those guys need more time in the minors. Hernandez may be up later this season, which seems like an ok timetable for me. If Chatham gets a cup of coffee at the end of the year, it would make sense too. It would just be weird to bring him up right now. Feltman, Shawaryn and Lakins will also probably be up at some point and those guys are ready to contribute sooner than later.