I suspect part of the thought behind Coach Tucker's statement was that a player who is eligible for a redshirt year is not necessarily invited to stay for a fifth year. Ros Gold-Onwude returned for a fifth year (it's said) only because Skylar Diggins turned down Stanford and decided to go to the University of South Bend, freeing up a scholarship.
p.s. Wikipedia has a detailed article about redshirt rules if you want all the gory details: http://en.wikipedia.org/wiki/Redshirt_%2..._sports%29
p.s. Wikipedia has a detailed article about redshirt rules if you want all the gory details: http://en.wikipedia.org/wiki/Redshirt_%2..._sports%29