Some of the main players were actually not deliberately rested by ancelotti, because since before the match started ancelotti had targeted a big win in the match to secure their chances of reaching the final, but several players who were sick and not in good condition forced ancelotti to play some of their reserve players in the match, in my opinion with a 1-0 victory it only makes them have to work hard in the second leg later to secure tickets to the final, so I think it would be a big loss if they failed to do so when they have the chance to do in the first leg actually,  indeed they will play at the bernabeu later but do you think real Sociedad has no chance to surprise us later?
Come on guys, anything can happen and we still have to think realistically because even a weak team can still give Madrid a negative result at the bernabeu so far.