Very very rarely. The only time it happens is if I know my winning fantasy (and normally making money) hinges on one player doing well and that player is playing SF. I've found myself hoping that the player I need does well but at the same time hoping SF wins. Of course in recent years, SF getting a win in and of itself was a task, so I seemed to find myself rooting for my FF player by halftime because SF had already taken themselves out of the game.
My Playoff Team - Please Comment
MSchaub, DMcNabb, JFreeman, KKolb
SJackson, THightower, CWells, JForsett, JSnelling, CJennings, QGanther
RWayne, RMoss, RMeachem, MCrabtree, DBowe