Yes Real Madrid didn't play well yesterday Vs Real Sociedad in their Copa Del Rey semi final game. Some players were missing form the squad, I don't know if it's because of injury or they were kept purposely by the coach for Saturday and Tuesday Champions League game Vs Atletico Madrid. Just this morning I read that Ceballos was injured and will be out for up to 2 months, another blow and bad news for Real Madrid considering their fixtures right now.
Why Real Madrid didn't play well? The won the match, right? I think there was no problem with Real Madrid performance. Yes, there were some main players missing from the lineup because of many reasons. Mbappe has a problem with his tooth, meanwhile other players may need time to take a rest. If Ancelotti rotated some players, I think it was good because Real Madrid has many important players in the near future. As long as Real Madrid won the match, I think Real Madrid already did their best. They can beat Real Sociedad with bigger scores in the next Leg.