5. Fitz Hall

Fitz Hall flipped the usual order here. Southampton had him young, Watford got him late, a 2012 to 2014 spell near the end of the road. A defender who saw plenty of dressing rooms in between, he's the one bridging these two from the back rather than the front.
Five players, two clubs, and a fair bit of shared history to chew on before kick-off. Saints Marching has the mood covered too, from the sold-out away end to the players with most to prove on Sunday.
If you'd forgotten that a Wales goalkeeper, two Watford-made strikers, a Chelsea loanee turned Southampton stalwart and a well-travelled defender all quietly bridge these two clubs, then consider the set complete before Sunday. None of them will be lining up this weekend, of course. But if you want a nice pre-match nugget for the pub, Super Kev knowing both ends of this fixture is a decent place to start.
