The two teams are set to lock horns on Saturday and it will be the first time that Alonso will play against the club he started his career with. Speaking on the eve of the occasion, the World Cup winner said that the Blancos are not taking Sociedad lightly and reiterated his faith in coach Jose Mourinho's system.
"Real Sociedad have a good coach who works his men hard," said Alonso, according to Realmadrid.com. "They also have a team built primarily of academy players, which makes their commitment even greater.
"They play with two central midfielders, [Mikel] Aramburu and [Diego] Rivas. I know them very well and they are hard workers, so we need to be very astute. We may have some difficulties if we aren't on top of our game. We will do our best to win.
"It will be special to play against my former team. I have been a fan since I was little and by the time I was ten I had season tickets and went to every game. Guipuzcoanos are very proud of their team. I think the mix of academy players and foreigners has really worked out."
The Spain international continued, "I feel very comfortable with the system used by Mourinho. It's a very dynamic 4-2-3-1 that can easily change to 4-3-3 or 4-1-4-1 depending on the moment or the team's needs. He really knows what he wants. He has been very successful, so there is no reason for him to change. I hope his streak continues here.
"I am a much more experienced and have learned a lot. I have improved with time by playing for elite teams in elite leagues and the Champions League, and with the Spanish national team in World Cups and European Championships. I have been progressing throughout my career, which is a very good sign."