When you are reviewing your team - remember one thing. Loyalty is fantastic and should be treasured but and it is a big but - contribution is key.
Don't let loyalty mask your view of the contribution that the person is making. Your role is to ensure that the loyalty is turned into performance - for me that is engagement.
Check out The Engaging Brand podcast and their blog for help if you feel you need ideas of how to achieve Engagement - well worth checking out.