No, the number should not be retried. The Castleberry argument has already been made and should be enough...but In general football numbers should not be retired for another reason
There's only 101 football numbers (though I don't recall ever seeing 0 or 00 used in football) and 85 scholarship players plus the walk-ons.
We already have two players for each of these numbers on our roster right now: 9, 11, 13, 14, 23, 27, 36, 38, 39, 47, 52, 57, 59, 66, 67, 68, 76, 77, 79, and 89. Unless the rule has changed and I wasn't aware of it, two players that wear the same number cannot be on the field at the same time.
You start retiring football numbers and you won't have enough numbers to field a squad.