Potter, Holt, A.Reid and Higgins can all play left back so we definetely don't need a left back. Holt is a left sided midfielder.
Our striking options at the moment are Parkin, Clark, Reilly, Brighton and Smillie. Haven't seen a lot of Smillie but he has got a bit of pace about of him. Brighton can operate at left midfield but he just isn't very good in my opinion. Clark and Johnston can play left mid aswell but Johnston has been good in central midield recently so i'd keep him there.