Always a concern with guys who aren't main men but good players in good teams. Another one of those buyer beard situations.
Look how Heffernan, Blumfield and Caracella went when they left that gun Essendon team of 1999 to 2002. Only Caracella maintained his form and maybe that was because he went to the Lions. Blumfield was poo at Richmond, ditto Heffernan at Melbourne.