Alonso watched as second-half brace from Williot Swedberg ensured Celta Vigo defeated the Los Blancos.
Real Madrid duo Fran García and Álvaro Carreras also received red cards during the encounter at the Santiago Bernabeu.
Speaking at his post-match interview after the game, Alonso admitted that Real Madrid were lacking in some areas against the visitors during the encounter.
The Spaniard also said that defender Éder Militão’s injury disrupted Real Madrid’s plans.
“We’d planned the match after the Bilbao game to play at a good pace and put pressure on a good side.
“We were lacking in some areas, and the injury disrupted our plans. We struggled to react; almost the best reaction was when we were down to ten men.”
Real Madrid will now turn their attention to the UEFA Champions League where they will face Manchester City on Wednesday.
