Aston Martin team principal Mike Krack has revealed Fernando Alonso was forced to lift and coast during the Canadian Grand Prix due to what appears to now be a bogus fuel system issue.

After a slow start off the line at the Circuit Gilles Villeneuve which resulted in the two-time F1 champion being passed on the run down into Turn 1 by Mercedes’ Lewis Hamilton, Alonso had to wait until lap 22 before finally reclaiming second place.

Alonso then set his sights on leader Max Verstappen but was unable to push the Red Bull driver as hard as he would have liked due being asked to lift and coast, even though he said over the radio he was going for the win.

At the chequered flag, Alonso finished just under 10 seconds behind Verstappen, the closest any driver has come a Red Bull this year, with the obvious exception of the Australian Grand Prix which finished behind the safety car.

Explaining the instruction to Alonso, Krack said: “We thought we had a problem with the fuel system but we were not sure.

“So as a precaution, we said it best to save some fuel and to do lift and coast. How much did it cost us? It’s difficult to judge, a few tenths probably.”

Krack has confirmed there was “enough” fuel left in the tank at the finish. Reiterating the fact the decision taken was “precautionary”, he added: “You can choose between not finishing or arriving with a bit more, so we wanted to be safe.”

Despite initial post-race checks, Krack revealed the apparent problem with the fuel system which had shown up in the data had “not materialised yet”.

Krack has dismissed suggestions made during television commentary that Alonso also had a brake cooling issue.

“I was surprised as well to hear that,” remarked Krack. “I think Lewis was told we had a brake situation.

“We looked at each other and we said ‘They know more about our car than we do. We should speak to our Mercedes engineers.”

Krack still feels Verstappen was managing his race enough that Alonso would not have got too much closer at the end.

“We were closer than lately, but maybe if we had got closer, he would have pushed more,” said Krack. “It’s very hypothetical.”

From Alonso’s perspective, he pushed himself to the limit throughout the race to score a crucial result that at least highlighted the upgrades on the car introduced for this race are working.

“It was a tough race from the beginning,” said Alonso. “We lost a place at the start I thought maybe was gone, and I would have to concentrate on the guys behind, George (Russell) and the Ferraris maybe.

“But then we were able to overtake Lewis and we had a little bit more pace in that part of the race. I was quite okay until the last 20 or 25 laps when Lewis was coming very fast.

“I had to push to the limit again. All in all, it was 70 laps of qualifying, there was no time to rest. And I loved it”.