The Spaniard was linked to a move to Barcelona over the summer, but no such deal was made.
Saul, 23, signed a nine-year contract with Atletico in 2017, and he says that he has every intention of honouring it.
Speaking to 'Radio Nacional España', Saul was asked about the huge contract, and whether he planned to see it through.
"That's why I signed a long-term contract," he replied.
"That's my intention, to be at Atletico Madrid all my life, but in the world of football you never know.
"For me, yes [I want to retire at Atletico], but maybe I have a bad couple of years and then they grow to not love me anymore.
Atletico have made a good start to the season, sitting one point off the top behind Real Madrid and Barcelona.
Apart from sitting on the bench for the comfortable 3-0 win over newly-promoted Huesca, Saul has played every minute of the season so far.