Ferrari has confirmed that the engine that failed for Charles Leclerc at the Azerbaijan Grand Prix is "beyond repair", raising the prospect of a grid penalty in the near future.
Leclerc retired from Baku's June 12 race while in a promising position to challenge the Red Bull drivers for victory.
He also suffered a power unit failure while comfortably leading May's Spanish Grand Prix.
Ferrari is not ruling out the possibility that the two failures were linked.
A statement Ferrari released on Friday said: "Investigation confirmed Charles' Baku PU is beyond repair. One possible cause of the failure is that it occurred as a consequence of the PU problem in Spain.
"We are now working on countermeasures to strengthen the package and the situation is under control."
Under the rules, F1 engines are split into six components.
Drivers have a set amount of each component they can use before incurring penalties.
Leclerc is now down on one whole engine from his pool and will likely need to move beyond the allocated amount at some point, possibly as early as Sunday's Canadian Grand Prix.
The first time a driver does this, they must serve a 10-place grid penalty, which is applied after qualifying of the event in question.
Leclerc has seen a once-healthy championship lead disappear over the past two months.
Leclerc has not won a race since the Australian Grand Prix on April 11 and has dropped 34 points behind reigning championship Max Verstappen.