Butch’s Minutiae Musings – Is assigning your best person to a task always the best solution?

A Project has a baseline (that is a timeframe to do a particular task. Any Project Manager will always want their best resource to be assigned to accomplishing important (critical) tasks. But what if your ‘best resource’ is feeling bored? burned out? Or what if they want to do something else? How will the Project Manager tackle this situation?