Carlos Sainz says a wrong strategy choice and "pushing too much too early" at the start of his stint on the medium tyre ruined his quest for points in the Portuguese GP.
Contrary to the majority of those starting in the top-ten, including his Ferrari teammate Charles Leclerc, Sainz launched his race on the soft tyre from fifth on the grid.
The Spaniard gained one spot at the start to the detriment of Sergio Perez and held his own during the opening laps of the race until the Red Bull driver and McLaren's Lando Norris pushed him back to sixth where he remained until his pit stop on lap 21.
The #55 Ferrari was the first contender to swap tyres, but that strategic decision - which aimed to undercut Norris - immediately proved costly.
"Honestly the race pace all weekend was looking good," explained Sainz. "I don’t think the race pace was the issue, it was just that we got it wrong with the strategy of pushing on the tyres and we didn’t get things right today.
"It was also looking decent up until [then]. We were putting pressure on Lando and we went for the undercut and unfortunately, we didn’t make it stick.
"We exited behind a Williams, I had to push really hard to try and do the undercut and we opened up the graining on the medium tyre," he added.
"We know how important those three laps at the beginning of each stint are and I pushed like hell to try and get the undercut on Lando and in hindsight, it was too much pushing too early, and trying too hard to try and get one position – and in hindsight we shouldn’t have gone for it."
As the graining on the medium tyre and degradation set in, a frustrated Sainz drifted to a lowly P11 at the end of the day.
"We were the first ones to stop to put the medium tyre on and the medium tyre today was not performing on our car – we opened the graining – and from then on we went backwards," he said.
Ferrari team boss Mattia Binotto who was hoping for a better result in Portugal admitted that the Scuderia could have perhaps "handled differently" Sainz's strategy.
"We tried an undercut with Sainz but it didn't work out and because of that he had to push too much and we had problems with tyre consumption," said Binotto. "It's not the result we thought or hoped for.
"Sainz maybe could have held back a bit more after the pit stop because he had plenty of time after that, but he and the team really wanted to overtake Norris so maybe we should have handled that differently."