Ahead of today's second practice session the air temperature is 27.3 degrees C, while the track temperature is 37.4 degrees.

Once again, in terms of upgrades, there's a new front wing flap and beam wing for Mercedes, a new rear wing for Red Bull, as beam wing for Ferrari and front and rear wing flaps for McLaren.

Alpine has removed its beam wing gurney, while Aston Martin has new front and rear wing flaps and Williams has a new single element beam wing.

AlphaTauri, Alfa Romeo and Haas have brought no updates.

Leclerc led a Ferrari 1-2 earlier, but like Mercedes, which saw its drivers finish third and fourth, the Maranello outfit is playing down its hopes for Sunday.

Of course, Hamilton's hopes have already taken a knock after taking on a new power unit which will see him start from the back of the grid, while Bottas, Tsunoda, Sainz and the Bulls also face penalties.

Vettel and Schumacher are back in their cars this afternoon, having handed them over to Nyck de Vries and Antonio Giovinazzi, respectively, earlier.

The lights go green and Sainz leads the way, followed by Vettel, Ocon, Alonso, Perez and Zhou. As more drivers emerge, most are on mediums, though Schumacher, Ocon and Ricciardo are on hards.

Sainz gets proceedings underway with a 23.156, as Perez goes second (23.332), ahead of Alonso and Zhou.

Moments later a 23.021 sees Verstappen go top.

Hamilton goes fourth with a 23.349 and Russell fifth (23.520), as Leclerc begins his first flying lap.

Quickest in all three sectors, the Monegasque crosses the line at 22.307 to go top by 0.714s.

Verstappen leapfrogs Leclerc with a 22.303, just 0.004s quicker.

Eleven minutes into the session, Bottas is the last driver to head out. The Finn subsequently goes fourth with a 22.993. however, he is the only driver on softs.

Russell goes fifth (23.023), ahead of Perez, Tsunoda and Hamilton.

Albon reports that his front-left is overheating.

For a while Bottas has the track to himself but then Haas sends out both of its drivers - both on softs - as it appears to be practicing tows for qualifying.

Magnussen subsequently improves to thirteenth with a 23.871.

Now the drivers start switching to softs, one of the first being Alonso. The Spaniard goes fourth with a 22.752, however he is demoted when Norris posts a 22.338 to go third.

Albon improves to sixth - which is some improvement - courtesy of a 22.835.

Verstappen locks-up at the first chicane as Ricciardo improves to 8th with a 22.911.

Despite that lock-up, Verstappen improves to 21.807 having gone quickest in the two final sectors.

The session is red-flagged when Schumacher stops on the approach to the first of the Lesmos.

Initially it didn't appear to be much of a problem, but then the German is urgently told to stop the car and park it by the right-hand side of the track.

The session resumes with 25 minutes remaining. Russell is first out, followed by Sainz, Ocon, Gasly and Perez.

Sainz wastes no time in raising the bare, the Spaniard going quickest with a 21.664.

Attention now focuses on longer runs on high fuel in anticipation of Sunday afternoon.

"Quite a bit more bottoming on the straights," reports Russell.

Told to "box", Leclerc says he prefers to do one more lap "to be honest".

Hamilton reports that his car is "unstable".

Another big, big lock-up at Turn 1 for Perez.

Norris is told to try a different line on exiting the second Lesmo, the Briton advised to stay on the left for as long as possible on the run to Ascari.

Currently 15th, Tsunoda has completed the most laps (22), ahead of Norris and Zhou (21), Ocon and Alonso (21).

"Deployment is a bit all other the place at the moment," reports Russell, only to be told that both cars are suffering.

With 8 minutes remaining, all bar Schumacher are on track.

Leclerc gets it wrong at the first chicane and has to zig-zag his way through the polystyrene markers.

Already facing grid demotion, Tsunoda is under investigation for failing to slow under yellows.

In quick succession Albon and Bottas take trips through the gravel. "Same place," admits the clearly frustrated Finn.

The session ends. Sainz is quickest, ahead of Verstappen, Leclerc, Norris, Russell, Perez, Hamilton, Ocon, Alonso and Albon.

Ricciardo is eleventh, ahead of Zhou, Bottas, Gasly, Tsunoda, Magnussen, Vettel, Stroll, Latifi and Schumacher.

So, despite the doom and gloom leading up to the weekend, Ferrari is looking a lot stronger than anticipated. However, those penalties are going to have an impact and there could be more to follow.

Check out our Friday gallery from Monza here.