Crawley Town are specialist giant killers.
I can't remember how many seasons ago (it's not many) they got through as far as playing the other team with Manchester in its name, at The Swamp (so called after Shrek, who used to live there).
They gave Ordsall Rovers a fair run for the money.
Your manager didn't want the inconvenience or the hassle of playing unwanted additional games when the focus is to stay in the Premier League.
I can't say as I blame him.
Liverpool went out of both domestic cups last season in the first game.
They were focused on trying to win the Premier League, only they didn't pull it off.
You have to balance the approach, and try to win everything