The 19-year-old Spaniard is making his F1 debut this weekend in Hungary, having replaced the ousted former occupant of his cockpit, Sebastien Bourdais.
But while the youngest ever grand prix driver is expected to remain with the Red Bull owned team in 2010, its boss Franz Tost at the Hungaroring confirmed reports that there are no guarantees.
When asked about the duration of Alguersuari's contract, Tost replied: "It is a very easy question. That is a decision of his right foot.
"The faster he is, the longer he will be in the car with us," the Austrian is quoted as saying by the Daily Telegraph.
Tost suggested, however, that the plan is a long-term one, contradicting rumors Bourdais was only ousted because of the backing on offer from Alguersuari's Spanish sponsors.
"Let me tell you it this way — he will be educated at Toro Rosso and then he goes to Red Bull Racing because this is the target," added Tost.