The Chile international moved to Barca last summer from Udinese.
"I would like to end my career as one of the best players in the world and to have brought the name of Chile to the world," he told the National Association of Professional Football (ANFP).
"But life is a challenge and most importantly, I am aware that I have not done anything yet and just have to carry on.
"So, I'll stay quiet and when I finish my career, I'll see what I did right and what I did wrong.
"It all depends on the mentality, and sometimes the mentality of the Chilean player is weak and gets carried away by many things.
"Sometimes he thinks he has already done everything even though he has not done anything. Chilean players are very good, but we need the right mentality."