He is expected to step up to Toro Rosso next year.
But Sainz's father, who is in Montreal this weekend, told the Spanish sports daily AS: "There's no hurry -- the later the better.
"I have had no notice from Red Bull or anyone regarding anything other than the (Renault) World Series for Carlos," he added.
After four rounds of the 2014 Formula Renault 3.5 series, Sainz jr is clearly leading the championship.
But his father Carlos Sainz continued: "We go step by step, with confidence, trying to do things right."
However, Toro Rosso team boss Franz Tost has acknowledged that Sainz does appear to have a future in F1 -- and logically one that starts with the Faenza team.
"Nothing is decided," he said, "but I think that sooner or later he will be on the track with us.
"I hope he drives with us on a Friday, but I cannot confirm this yet because we are still early in the season and trying to solve our reliability problems.
"Carlos will be in the car one Friday," Austrian Tost then added.