So what would have been the downside in taking Fernandinho off after 80 minutes and bringing Doyle on for example?
Fernandinho has barely played this season and is captain. Why not play your captain a full game when you are going to need him? Any minute on the pitch counts when you have been out for many weeks. We are playing 2 games per week now and we need any of the senior players in as good form as possible. Fernandinho is one of the players we will rely on over the next few months. It's not like Pep doesn't want to play youngsters. The rules of professional football, especially at top top level, are different.
Youngsters Pep has played this season: THB, Doyle, Palmer, Delap, Bernabe, Nmecha. Plus U20 players like Foden, Garcia and Torres.
That's 9 very young players. 9!
Note the players Klopp subbed in yesterday: Robertson, Henderson, Mane, Firmino...Why? Because results (in the CL) matter and mean money.