"he played LB for Internacional and that's his natural position"
I really doubt anyone here said Juan is a natural LB.
I thought he was great.
Perhaps, you guys are forgetting the fixtures we had since RM was appointed, IIRC mid November.And Mancini has taken the team to mighty 10th place... By getting worst results than Mazzarri. Right move indeed.
Perhaps the right move was giving Mazzarri the full season then conducting a real search for a replacement. Not just any big name who was out of a job.