McLaren stand-in driver Pedro de la Rosa is set to keep his seat for the final four races of the 2006 season.
De la Rosa has proved a solid replacement for Montoya
The Spaniard has been McLaren's number two behind Kimi Raikkonen since Juan Pablo Montoya left in July after announcing a move to Nascar in the USA.
McLaren team boss Ron Dennis said: "He will definitely race at Monza and most likely the rest of the season."
The decision means young British duo Lewis Hamilton and Gary Paffett are unlikely to be handed a race this year.
Paffett and Hamilton are both test drivers for McLaren, and Hamilton, 21, was heavily tipped to be promoted by Dennis.
But the team chief said: "We are not in the business of developing Grand Prix drivers, we are in the business of winning races.
"The place to develop young drivers is not in the pressure of Grand Prix racing."
Since taking over from Montoya, De la Rosa has finished seventh at the French Grand Prix, retired in Germany but taken second spot in Hungary behind Britain's Jenson Button.
McLaren have not yet decided who will race alongside the incoming Fernando Alonso in 2007.
The team want to keep Raikkonen but he has been linked to Ferrari, as a possible replacement for Michael Schumacher should the seven-time world champion decide to retire.