Iturraspe's form for Bilbao last season earned him a spot in Spain's preliminary World Cup squad, but he failed to make the final 23-man cut.
La Roja boss Vicente del Bosque included the midfielder in his latest selection, however, and he has been tipped to play a part against Macedonia this evening.
"This is the second time for me and I feel much more comfortable and settled. What has surprised me the most has been the sessions of 'piggy-in-the-middle' in training, I can't believe how quickly the ball is passed about," he told AS.
"It's a pleasure to be here; at first you have a few doubts about how the rest of the players will take to you but everyone is very normal and natural, just like me.
"I have been welcomed on board by everybody. It's difficult to get into the Spain squad because the standards and the quality of the players is so high. I have to train hard so that I can be at my best level and enter into the side little by little."
Iturraspe is one of a number of new faces in the Spain squad.