The South Americans booked their place in the second round by beating Spain 2-0 at the Maracana on Wednesday night to send the defending champions out of the tournament.
Although Sampaoli praised the "maturity" of his Chile team for such a scalp, the 54-year-old erred on the side of caution when asked just how far his side could progress in the competition.
"It seems to me that this group prioritises the collective and that has to be dangerous for anyone," he told reporters.
"It was tough to play against a Spain who needed a result so much. This team has found a level of maturity. It doesn't pass through my head at all that Chile could be world champions. We need to go game by game."
Chile, who sit second behind the Netherlands on goal difference in the pool, face Louis van Gaal's side on Monday to determine which team goes into the last-16 as group winner.