But thats the thing. Tracey was never a 'back up' keeper. For spells he was a first team keeper who just so happened to be being kept out of the team at that time by another player (Kelly) in his position.
Tracey was the undisputed number one for Utd after replacing Graham Benstead in the 88-89 season. He remained number 1 until Kelly arrived on the scene in 92 from Preston.
The reason some tend to think of Tracey as being the 'back up' keeper, was that he had more injuries than Kelly. When he got back to full fitness, he couldn't get back into the side cos Kelly was such a good keeper and in form. Likewise, on the less frequent occasions when Kelly was injured, Tracey held the spot as number 1 keeper, keeping Kelly out of the team when he was fit again, until Tracey's injuries (usually his shoulder) resurfaced again. Only towards the end of Traceys career at the Lane was it apparent that injuries had taken its toll on him and then and only then was Kelly the undisputed top dog.
Both were number 1 keepers in their own right, both were fantastically gifted players, and neither could be classed as a 'back up' to the other. Between them they ensured that Utd kept a fabulous keeper in between the sticks for nearly a decade. The thing is it worked so well. Both waited for their chance and had to sit on the bench for a time, and when they got their chance invariably it was only their injuries which gave the other his chance. It meant that both stayed on top of their respective games.
Utd dont need a keeper who makes a living out of 'covering' for another keeper. They need a new keeper who is confident enough in his own abilities to think that he he should be the undisputed number 1. Then it's down to new boy and Moore to battle it out ala Kelly and Tracey did back in the day for that first team spot. Competition for places doesn't do any one any harm, it keeps em both sharp and on their toes.