The pair worked together at Malaga.
"I find it strange that some people don't know about him," the Spaniard told the official Arsenal Magazine. "He's done spectacular things with Malaga and Villarreal in the Champions League. Clubs like City obviously want him for a reason and, ultimately, it's for the job he's done.
"He's demonstrated he is top class. At whatever team he's been at - Malaga, Villarreal, Real Madrid - he's done well. He's had those teams playing spectacular football and I'm sure City will be a better team. I'm sure City's football will change and will be more offensive.
"I'm very happy for him because he deserves to be at a club of that level. He's getting his reward. He's been so important to my career."