Fernando Alonso says he has no issue with Sebastian Vettel angrily swearing about his driving on Friday in Mexico because the German is "living a very frustrating period" at Ferrari.

Vettel replaced Alonso at Ferrari last year but despite three wins in his first season the team has failed to make the top step in 2016. Technical chief James Allison left the team before the summer break and Vettel's relationship with team boss Maurizio Arrivabene has come under scrutiny in recent races.

During FP2 in Mexico Vettel, who went on to top the session, complained frequently about traffic, and at one stage got bottled up behind Alonso's slow-moving McLaren through the final sector. "What an idiot," Vettel told Ferrari on the radio, before calling the Spaniard something censored by Formula One Management's broadcast.

Reacting to that after the session, Alonso told reporters: "I heard what Vettel said on the radio but I don't make an issue out of it. He's living a very frustrating period, for himself and for Ferrari, so we have to forgive him."

Vettel himself said the traffic felt like he had been driving in Mexico City itself and not the Autodromo Hermanos Rodriguez.

Alonso and teammate Jenson Button finished FP2's qualifying simulation in 10th and 12th respectively. Like Button, Alonso does not think it would be the worst thing for McLaren to miss Q3 on Saturday as everyone continues to struggle with the super-soft tyre.

"The energy recovery was working very well in both cars, I think we have a good system as we could show in our small battle with Williams, Toro Rosso and Haas. For sure it works better in the race than in qualifying, so tomorrow ill he harder for us but we'll be stronger in the race.

"We should suffer a bit more here than in Austin, today it will be difficult to be 10th and 12th, as today, but we have a few changes in mind to try in FP3 and see how it goes. Given the degradation we had on the super-soft today maybe it's better to stay out of Q3 - starting in 11th and 12th places remains our virtual pole position.

"Those starting from the top ten will have to start the race with super-soft tyres and from what we saw today may have to pit on lap five, eight or ten -- too early. If we are right behind the top ten in qualifying, that would be ideal to have a good race."