MONTREAL (REUTERS) - Ferrari's Charles Leclerc faces a grid penalty, possibly at Sunday's Canadian Grand Prix, after a failed power unit that wrecked his race in Azerbaijan last weekend was declared a write-off.

Ferrari said the unit was damaged beyond repair and the problem may have been linked to an earlier one at the Spanish Grand Prix.

A spokeswoman said the team were working on "countermeasures" to strengthen the package.

Leclerc has plunged from Formula One championship frontrunner after three races to third overall, 34 points adrift of Red Bull's Max Verstappen, after eight of 22 rounds.

He has retired from two of the last three races with power unit problems, despite starting the last four from pole position.

The Monegasque told reporters ahead of practice for the Canadian Grand Prix that no decision had been taken on when to take any grid penalty triggered by exceeding the season's allocation of power unit components.

"Obviously we are not in the best situation possible," he said.

"For the power unit change, I think there are still ongoing discussions.

"We'll try and push as much as possible the decision, so for now no decisions are taken."

Leclerc said Canada was not a bad place to take a penalty, given that overtaking was quite easy, but some other circuits coming up might be better.

"We'll discuss that and try and take the best decision from there," he added.

Leclerc has so far used two of his allotted three engines but was on his third turbocharger.

Using a fourth turbocharger would trigger an automatic 10-place grid penalty from wherever he qualified on Saturday.

Ferrari can avoid an immediate penalty by using salvageable components from already used power units.

Ferrari had sent the engine that failed in Baku back to their Maranello factory for assessment.