Ferrari Team Principal Frederic Vasseur has explained concerns over the life of the Medium tyres was why Charles Leclerc could not match Lewis Hamilton in the Mexico City Grand Prix.
Leclerc was running a comfortable second at the Autodromo Hermanos Rodriguez, on a one-stop strategy and would have cycled into the lead once two-stopping leader Max Verstappen pitted again, with Hamilton in third place.
However, the red flag for Kevin Magnussen's high-speed accident at the halfway point presented teams with a dilemma over whether to opt for the racier Medium tyres that could wear out or the Hard compound Pirelli that would be slower but could easily get to the end.
Hamilton went for the Mediums and five laps after the restart, sliced past Leclerc into the Turn 1 braking zone to grab second place, with the duo going on to complete the podium behind Max Verstappen.
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Hamilton himself was concerned about the tyre life of the Medium C4 rubber, but the Mercedes driver was still able to finish nine seconds ahead of the Ferrari.
When asked about why Ferrari had not opted for the Medium with Leclerc, boss Vasseur explained it simply did not think the tyre would last the 35 laps.
"Honestly, because the restart was 35 laps and we were not expecting to be able to do 35 laps [on the Medium tyre]," Vasseur told media including RacingNews365.
"That was the maximum for the Medium, and with a bit of tyre management, management for the engine and the brakes, it was ambitious."
Leclerc pitted for his mandatory stop on Lap 32, just before Magnussen's crash and subsequent red flag for barrier repairs.
As tyre changes are allowed under red flag conditions, had Leclerc not-stopped, he would have taken the restart from pole, with Vasseur detailing a drop in performance after the restart.
"What happened two laps after we stopped was the red flag and we would have restarted from pole position," Vasseur added.
"It's so and so as races like this have tons of events but the feeling is that we were able to match Max and that we were probably a bit faster than Lewis in the first part of the race, and then we lost the pace on the second stint and the only difference is the compound [of tyres]."