Daniel Ricciardo has already lost one of his new Formula 1 engines introduced for this weekend's Italian Grand Prix after suffering a failure in final practice at Monza.
The Australian was initially informed of a problem with the Renault power unit and instructed to return to the pits without shifting gear midway through the session.
But he was forced to stop trackside at the second chicane with the team telling him to only use the brakes to shut the engine down.
Red Bull, which performed a double engine change this weekend to increase its pool of units for the upcoming races, will now revert to the first new unit as no further new engines are available.
"It looks like it's something terminal on the engine, so it looks a certain engine change," Red Bull boss Christian Horner told Sky Sports.
"Unfortunately we don't have any more [additional] engines, so we have to put the engine back in from yesterday.
"It looks like an engine that has been lost unfortunately."
Ricciardo ended the session 20th and last while his team-mate Daniil Kvyat was 17th.
After the hefty penalties incurred from using two new engines, both are set to start from the back of the grid on a track where Renault's lack of power will be amplified.