The reality is that if the Rangers are struggling to find a way to get Murphy ABs, that's a good thing. That means that Josh Hamilton and Vlad Guerrero are healthy and productive, and Nelson Cruz and Julio Borbon are playing well.
Grant suggests that Murphy could get some playing time at first base against lefties, but that doesn't really make a lot of sense to me, since Murphy doesn't hit lefties any better than Chris Davis does. Getting Murphy playing time at first base makes some sense if Davis falls on his face again and Justin Smoak isn't ready, but sitting Davis lefties so Murphy can start there is problematic.
At the end of the day, I suspect that finding playing time for Murphy won't be an issue. I don't think Vlad is going to start 150 games at DH, I imagine Josh Hamilton is going to have to sit from time to time, and and the end of the year, Murphy will probably have 300-400 PAs.