Ahead of today's second practice session the air temperature is 18.9 degrees C, while the track positon is 38.1 degrees. While bright and sunny, it is also very windy.

Valtteri Bottas topped the timesheets earlier, edging out Max Verstappen by just 0.025s. However, the Dutchman wasn't entirely happy with his car, as was the case with Lewis Hamilton who was fifth quickest.

Sergio Perez was third quickest, while Charles Leclerc was fourth, Pierre Gasly sixth and George Russell a very impressive seventh.

While the fastest times were posted on the softs, we saw hardly any use of the mediums, which in fact was the go-to tyre in qualifying last year.

Having handed his car to Calum Ilott earlier - the Briton having made a very impressive FP1 debut - Antonio Giovinazzi is back in the second Alfa this afternoon.

Once again, track limits make the news, with a number of drivers having their times deleted for taking advantage at Turns 1 and 4.

The start of the session is delayed by ten minutes due to an issue a loose drain cover.

Sure enough, ten minutes later the lights go green, with the Alfa pair leading the way.

Soon there are 15 drivers on track, all but one (Mazepin) on mediums. Indeed, moments later all twenty drivers are on track.

Ocon posts the first time of the afternoon, a 21.687, but this is quickly beaten by Leclerc (21.294).

An early off for Mazepin (who else?), momentarily brings out the yellows.

A 20.937 sees Verstappen go top, ahead of Leclerc, Ocon, Sainz and Gasly.

However, Hamilton and Perez are on hot laps, as is Bottas. The Mexican goes fourth (21.185) as Sainz goes top (20.831). However, Bottas posts 20.805 and Hamilton 21.441 having lost time in the final sector due to traffic.

As he pits, Verstappen complains of a brake-by-wire failure. "What the hell?" says the Dutchman.

"I need less... I need more engine braking," warns Mazepin.

Bottas consolidates his top spot with a 20.423 as Hamilton improves to third with a 20.508.

Verstappen is the only driver not on track.

Raikkonen is the first driver this afternoon to have his time deleted, the Finn having erred in Turn 1.

"All the drivers out on the mediums (with the exception of Mazepin)," says Pirelli. "This morning, they generally went from hard to soft, saving the medium running for this session: the most representative one. Teams clearly think it will be very important to gather good data on this compound."

Gasly complains that he is lack rear grip at low speed.

Back on track, Verstappen wastes no time in returning to the top of the timesheets, the Dutchman posting a 20.322.

The Mercedes pair switch to softs, as do the Ferrari pair.

Bottas retakes the top spot with a 20.181.

Verstappen improves (20.257) but remains second to Bottas.

Ricciardo's race engineer, Tom Stallard continues to talk the Australian through his laps, much as he did earlier. Indeed, he reminds Ricciardo of things they'd tried in the simulator during the week.

A 19.837 sees Hamilton go top, as Russell improves to 13th with a 21.026.

As Hamilton looks set to improve, Alonso goes fourth with a 20.220.

As was the case in Italy two weeks ago, Tsunoda appears to have gone a little off the boil. Currently 16th, the Japanese has yet show the magic we witnessed in Bahrain.

Back on track, Verstappen goes second with a 19.980 but remains 0.143s off Hamilton's best.

After 35 minutes, the top 6 - Hamilton, Verstappen, Bottas, Sainz, Alonso and Ocon - are covered by just 0.398s.

Even the haters must surely feel a little sorry for Mazepin. As he is advised that he's had his time delated he swears. "I know I'm slow, I'm just trying to keep it on track."

Attention switches to Sunday afternoon, and Bottas is told that "the first four laps are critical".

"Something weird just happened," reports Schumacher, "the power out of Turn 4." Told to slow the car, he obeys, and makes his way back to the pits.

"These tyres are not good," complains Hamilton. Indeed after just 15 laps, the world champion appears to be struggling for grip. Indeed, he has his latest time deleted.

He subsequently pits and switches to mediums.

Asked how his front wing is, Ricciardo says it is "still a little high".

Mazepin has three successive lap times deleted for exceeding the limits at Turn 1.

However, the Russian is in good company, for Hamilton and Verstappen have times deleted also.

Even though the session is almost at an end, Stroll heads out with the rear wing on his Aston smothered in flo-vis.

The session ends. Hamilton is quickest, ahead of Verstappen, Bottas, Sainz, Alonso, Ocon, Leclerc, Ricciardo, Stroll and Perez.

Gasly is eleventh, ahead of Norris, Russell, Tsunoda, Vettel, Raikkonen, Giovinazzi, Schumacher, Latifi and Mazepin.

Check out our Friday gallery from Portimao, here.