The former Real Sociedad captain joined the Gunners in August after helping Spain win the Euros.
He said at his Champions League media conference yesterday: "I think we have a pretty complete team, a pretty complete coaching staff as well, they all have that winning mentality as well. They might not have the experience yet because we have a really really young team.
"Luckily, I’ve had some experiences where I won. So the experience when you have the moment of truth, when you’re in the final or semi-finals, to be able to keep that mentality, to keep that calmness and try to do whatever you’re doing on a daily basis that has made you get to that stage."
Ahead of tonight's clash with Shakhtar Donetsk, he continued: "Obviously, when you come here you want to make an impact, you want to prove why they signed you and you want to start building up that confidence and that relationship with your teammates.
"But I think, after the injury, everybody helped me so much, not only the players but the staff, the fans as well, I felt the love immediately and that helped me a lot to recover as fast as possible and at the same time to build a relationship with the whole team. So I feel like, right now, I’m at a good stage. Obviously not at the best one, but I’ll get there."