The former Chile international thinks that Sanchez wants to win the biggest prizes in football and he should play for a side that can match his ambitions.
"He's a guy who has goals and ambitions, they're fundamental to making a choice. I think he likes to win," he said.
"What he wants, above all, is to win the Champions League, and I don't think he'll have that possibility at Arsenal.
"He must know that he will be more useful in a bigger team."