Carlos Sainz was bewildered by the dismal lack of grip of his McLaren during his stint on the hard tyre that ruined his Mexican Grand Prix on Sunday.
Both Sainz and teammate Lando Norris, who had qualified respectively P7 and P8, enjoyed a good start to their afternoon, with the soft-shod Spaniard fending off Lewis Hamilton in the opening laps as he made good use of his tyres.
But after Sainz's switch to the hard compound on lap 15, it was all downhill from there as the McLaren progressively lost its edge over its midfield rivals, much to the annoyance of its driver.
"I cannot explain it at the moment," Sainz said.
"It's been a very frustrating afternoon because I kept fighting through the whole race.
"But unfortunately, after such a great start and managing pretty well the soft tyre, managing to get into lap 15-16 which was the target, immediately I felt we had no rear grip on the hard and I just started going backwards."
©McLaren
Sainz eventually gave up on the hard compound after 20 laps and switched to the medium rubber for his third and final stint, by which time his prospects of finishing in the top 10 had vanished.
"It was a step in the wrong direction with the tyre and we lost pretty much the race in that [second] stint.
"We need to analyse in detail what happened and why we had such a poor stint on that compound.
"Austin is right around the corner so there is no time to lose. We’ll keep our heads down and work hard to come back stronger next weekend."
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