Ahead of today's sole practice session the air temperature is 22 degrees C, while the track temperature is 39 degrees.

While this morning's session, like FP1, is unrepresentative due to the fact that it takes place in completely different conditions to what can be expected for qualifying and the race, it will allow the teams to carry out some much needed work.

None more so that Mercedes, which, unless the team is seriously targeting an Oscar, really does appear to have problems. Other than porpoising the W13 remains a best to handle, and the knock-on effect on pace has left Hamilton and Russell struggling. Indeed, a DRS issue left the seven-time world champion 0.7s adrift of his teammate yesterday.

Another team with "work to do" is Mercedes, which is still working on the brake cooling issues seen in pre-season testing.

While Ferrari appears to be the biggest threat to Red Bull, certainly while Mercedes sorts itself out, Alpine is looking good, as are Haas and Alfa Romeo.

The lights go green and Magnussen leads the way, followed Zhou, Bottas and Schumacher. All four are on hards.

Unsurprisingly, Hamilton is another early riser, followed by his Mercedes teammate.

Russell is told to check his DRS, probably a wise move following Hamilton's issues yesterday.

Zhou gets things underway with a 38.886, though Bottas responds with a 38.840.

The pair head back to the pits and a brief lull ensues.

Ten minutes in and there are only two times on board, with only six drivers having ventured out.

At which point Norris and Hulkenberg head down the pitlane, followed by Hamilton. While Norris and Hulkenberg are on mediums, Hamilton is now on softs.

The three trade fastest sectors, Hulkenberg crossing the line at 37.506, Norris at 36.317 and finally Hamilton at 34.256.

Russell heads out on the red-banded rubber, followed by Sainz and Leclerc, also on softs.

"Any porpoising," Hulkenberg is asked. "No, no," he replies.

Bottas goes second (34.617), but is demoted when Russell crosses the line at 34.470.

Quickest in the first two sectors, Leclerc crosses the line at 33.797, with Sainz taking second with a 34.217.

Perez, Gasly, Albon and Stroll head out the four on a mixture of compounds.

"Brake pedal is a bit long, it's a problem," warns Perez. Nonetheless, he goes second with a 34.160.

With 40:00 remaining, Verstappen finally heads out, the world champion sporting softs.

Albon goes eighth, ahead of Norris, Gasly, Stroll and Hulkenberg.

Norris, incidentally, is sporting flo-vis on the front of his McLaren.

As Verstappen goes quickest in S1, Tsunoda remains the only driver yet to appear, though only 12 drivers have posted times.

Verstappen stops the clock at 33.035, 0.762s up on Leclerc and 1.221 on Hamilton.

"I don't have any stopping power," complains Perez, which, one has to say, sounds a bit of an exaggeration.

A big off for Leclerc at Turn 11, the Ferrari driver lucky not to clout the barriers. He heads back to the pits.

The top twelve times were all set on softs, the quickest medium runner being Norris who is 3.2s off Verstappen's pace.

Gasly improves to 13th (36.088) on the mediums.

In the AlphaTauri garage Tsunoda's car is up on its stand, the team having traced a hydraulics issue.

Schumacher goes 9th with a 34.629on softs, while teammate Magnussen is sixth - yes sixth - on 34.263. The other Ferrari powered team - apart from the obvious - Alfa Romeo, is currently 8th (Bottas) and 10th (Zhou).

"The fronts were gone after four corners," reports Albon who is on softs.

Hmm.. Hamilton goes quickest in S1, and while he can only manage a PB in S2 he crosses the line at 33.121 to go second, just 0.086s off Verstappen's. That said, we have yet to see the Dutchman give it "full beans".

With 20 minutes remaining, other than Hamilton, just Sainz, Perez, Albon and Ricciardo are on track.

Hamilton is told that his main loss to Verstappen is in Turn 10.

Albon improves to 10th with a 34.868.

On fresh softs, Sainz improves to 33.053, thereby splitting Verstappen and Hamilton. The Spaniard is quickest in the final two sectors.

Russell goes quickest in S2, as Verstappen heads out. Quickest in the final sector, Russell goes top with a 32.935.

Elsewhere, Bottas goes fifth and Zhou seventh.

A lock-up in Turn 1 sees Verstappen abort his lap.

Norris improves to 8th (33.955), as Leclerc goes quickest in S2. At the line the Monegasque posts 32.640 to go top by 0.295s.

Game on!

Verstappen goes quickest in S2, crossing the line at 32.544 as he goes 0.096s quicker than Leclerc.

The top five, Verstappen, Leclerc, Russell, Sainz and Hamilton are covered by 0.577s.

Perez remains ninth, 1.616s off the pace.

"Lap isn't great, especially last sector," reports Leclerc. "I think we will be missing a bit compared to the others."

Perez improves to third with a 32.791, 0.247s off his teammate's pace, the Mexican having been quickest in the opening sector.

An obstinate front-left means a long practice stop for Verstappen.

A 34.378 sees Ricciardo improve from 17th to 11th, the Australian just 0.3s off his teammate's pace.

Other than Tsunoda, who has not appeared, the Aston Martins are holding up the timesheet.

At which point Stroll goes ninth (33.920) and Hulkenberg 11th (33.971).

That was nice," says Alonso's engineer as Sainz is released directly into his path in the pitlane. The incident is noted by the stewards.

As Schumacher improves to 14th (34.295), teammate Magnussen posts a 33.437 to go seventh.

The session ends. Verstappen is quickest, ahead of Leclerc, Perez, Russell, Sainz, Hamilton, Magnussen, Bottas, Zhou and Stroll.

Norris is eleventh, ahead of Hulkenberg, Gasly, Schumacher, Ricciardo, Alonso, Albon, Ocon, Latifi and Tsunoda.

So, other than Mercedes being back in the mix with Red Bull and Ferrari, we have the added prospect of Haas and Alfa Romeo worrying the likes of McLaren in the midfield battle.

Never mind talk of qualifying answering a few questions in terms of the pecking order, it threatens to be a genuine thriller.

Check out our Saturday gallery from Bahrain, here.