McLaren will not rush in to handing British GP2 champion Lewis Hamilton his first Formula One drive at the season-ending Brazilian Grand Prix.
Hamilton will test again in Jerez before his future becomes clearer
After an impressive Silverstone test Hamilton could replace Pedro de la Rosa in Interlagos but McLaren are cautious.
Team boss Ron Dennis said: "I can't see throwing him in at the deep end is a particularly smart thing to do.
"I would rather see Lewis as equipped as he could be to have a chance of racing for McLaren in the future."
Hamilton, 21, showed he could handle the pace of an F1 car with an encouraging performance in his first two-day test for the team last month.
The Stevenage-born driver will get a second chance to prove himself when testing takes place in Jerez next week.
However, Dennis insists that testing alone will not decide whether Hamilton or De la Rosa will drive alongside the outgoing Kimi Raikkonen in Brazil.
"We are not going into the test to evaluate Lewis' abilities as a driver," said Dennis. "That is not the objective.
"It is to give him more mileage on a different type of circuit. No decision has been taken but as and when it is we will announce it."
McLaren have yet to decide who will race alongside the incoming Fernando Alonso in 2007.
De la Rosa has been very solid since replacing Juan Pablo Montoya, who left to join the US Nascar series, at the French Grand Prix.
McLaren could prefer to pair the experienced Spaniard alongside his compatriot Alonso next season.
However, Hamilton has long been considered a real talent by McLaren after signing to their development programme at the age of 13.