We can't afford to take risks and rotate too much either, Luton are a difficult side to play against.
I think Darwin doesn't get a look in until the final, if his injury isn't too serious. Diaz,Gakpo,Salah up front, and Harvey to come on later in the game, for one of them.
I thought Ryan did well when he came on for Curtis, so I'd say the midfield stays the same potentially.
Think Gomez comes in for Robbo, so he isn't playing 3 games in a row.