Red Bull Racing and Toro Rosso head to Abu Dhabi next week hoping not to be impacted by a spare parts crisis which has hit engine supplier Renault.
A painful series of power unit failures has wreaked havoc on the French manufacturer's inventory of engine components, elements which simply cannot be produced on short notice.
Red Bull's engines were tuned down in Brazil last weekend to safe-guard reliability, much to Max Verstappen's displeasure after his great run and triumph in Mexico.
"We are glad the engines survived," Red Bull's Christian Horner told Auto Motor und Sport.
Asked what will happen if parts fail in practice in Abu Dhabi, he answered: "We don't want that to happen. It would be an expensive job to sort that out."
Horner made clear that he does not blame the actual Renault mechanics, who have been working particularly hard at recent races, for the recent spate of failures.
"What the Renault mechanics have done is a small miracle," he said.
"For weeks they have been making old parts workable and screwing them on from one car to another."
Toro Rosso has been more severely impacted by Renault's recent mechanical failures, a state of affairs which generated huge tensions between the Faenza-based squad and its supplier.
On behalf of Red Bull, Helmut Marko moved to try to appease the anger expressed from both camps but said neither team is happy with Renault.
"Of course it's not satisfactory," he said.
"They did not solve the problems and parts are running out. Unfortunately Toro Rosso was affected more than the other teams and that's why emotions were high.
"But we discussed it, made a statement and everything is ok."