IMO Ramsey made some crucial mistakes last night, both selection and unforced substitutions.
He started with 3 players that have shown they can‘t play full 90 minutes, Sandro, Zamora and Hoilett.
He started a rookie at right back when he had seasoned international at his disposal.
99% in here knew when Kranjcar came in it was match over and then he had to bring in Isla to help Furlong. Zamora could not jump after 60 and he is only in the team for jumping.
Having Isla and Zarate in the starting line up would have made it easier for him. He had no other option than bring Hill on. But he could have brought in Zamora for Sandro with Zarate dropping back and the Vargas/SWP when Hoilett was done.

Of course injuries and bans did not help him. For fun I pick a time out of injuries/bans/not used players and come up with IMO not so bad team.
Zarate- Fer