"I have always said my last team will be Barca," said the 32-year-old.
"I have absolutely no intention of wearing any other shirt because... I have been a 'Cule' all my life. For me, being at Barca is the biggest dream of all.
"My intention is to get to 2022, but I don't have a crystal ball and I don't know if I'm going to be able to do it.
"If I see that I lose importance or see that I am not at the [required] level, I have no problem leaving earlier.
"I don't think it will happen because I know myself and I am able to endure until 2022, but you never know."