I thought the team played it's best basketball running with the three-big rotation of JV/Amir/Patterson, and in that situation, I think most definitely that Amir should be starting.
Playing 4 bigs...in addition to being hurt, Amir just seems to struggle more getting in the flow. Also, Patterson and Hayes/Hansbrough really lack length and struggle defensively when on the court together. If Casey plans on going with 4 bigs in the playoffs, I would understand bringing Amir off the bench.
But I think Amir needs to be a big factor if this team is going to have playoff success, so I hope Casey keeps Amir in the starting lineup, and I hope he picks another stretch or two of games where he runs with a shortened bench and a 3 big rotation up front and runs with that in the playoffs.