Button issues aside, George Russell is third quickest with a time of 1:09.240 on a set of red-banded soft tyres.

George Russell is the latest driver to jump on he radio to report issues. The Mercedes man says he is pressing the overtake button "many times" but nothing is happen, even though his engineer states it should be working now.

"What's going on with the engine?" asks Charles Leclerc to his Ferrari engineer. The Monegasque driver is told he can box the lap, but the 24-year-old, on the medium tyres, decides to stay out.

1. Max Verstappen (Red Bull) - 1:08.966

2. Carlos Sainz (Ferrari) +0.184s

3. Charles Leclerc (Ferrari) +0.605s

4. Pierre Gasly (Alpha Tauri) +0.863s

5. Lando Norris (McLaren) +1.153s

While George Russell peeps his nose out for an opening run around the track, a new floor is being lifted across the back of Lewis Hamilton's side of the Mercedes garage.

There are 34 points on offer this weekend for any driver who can complete the clean sweep of sprint win (eight points), race win (25 points) and fastest lap (one point).

Max Verstappen, who collected full marks at Imola at the first sprint weekend of the season at Imola in April, goes quickest with a 1:09.067.

A couple of times in the 1:11s, Lando Norris in the 1:10s, but Charles Leclerc in the Ferrari is top of the timing sheets with a 1:09.620 on the medium compound.

Norris is also joined by team-mate Daniel Ricciardo, the Red Bull pair, Nicholas Latifi and Yuki Tsunoda on the red soft tyres.

Medium tyres bolted on for most of the early runners but Lando Norris has opted for softs after missing the majority of first practice on Friday.

After the hardest tyres in the range were used at Silverstone, it's the softest compounds Pirelli have nominated for this weekend's Austrian Grand Prix.

Image source, Pirelli motorsport

Plenty of working going on in the Mercedes garage, but the gates are open for the rest of the pack.

One hour of rehearsal time left.

Andrew Benson
BBC Sport’s chief F1 writer

Mercedes "hope to be running midway through the session". In addition to Hamilton's new chassis, both cars have different gearboxes, from within their permitted pool. Floors and wings have been repaired and/or swapped. Engines have been thoroughly checked - and nothing replaced.

Lando Norris only completed 14 laps in his McLaren during first practice before having to get out of the car, pat down hot posterior and head back to the garage to watch the rest of the session on the monitors.

In a disheartening day all round for McLaren, the 22-year-old qualified 15th on the grid for this afternoon's sprint event due to issues with braking, while team-mate Daniel Ricciardo starts one place behind in P16.

BBC Radio 5 Live Sports Extra

Jack Nicholls is joined by reigning W Series champion and Williams F1 development driver Jamie Chadwick for Saturday's track action, along with BBC Sport's chief F1 writer Andrew Benson.

Second practice is available to listen on BBC Radio 5 Live Sports Extra, the BBC Sounds app and at the top of this page by clicking the audio icon.

Andrew Benson
BBC Sport’s chief F1 writer

Image source, Getty Images

A theme of this season has been an undercurrent of dissatisfaction from teams and F1 with the way governing body the FIA is running the sport, and part of that theme has been inconsistency and the general standard of decisions from race control and stewards. This weekend, there are already two more examples.

First, the Sergio Perez situation. The Red Bull driver was shown on television crossing the white line twice during his final lap in second qualifying - the only one that ensured he progressed. Yet this was not picked up by officials at the time. So Perez progressed into Q3 - at the expense of Pierre Gasly - and was only disqualified from it hours later, dropping him to 13th on the grid for the sprint.

Secondly, the issue of pit entry and exit. Readers may remember that Ferrari protested Max Verstappen and Perez after the Monaco Grand Prix because part of their outside wheels had crossed the white line on pit exit during the race. The drivers were not penalised, because the part of the sporting code that refers to this had been updated over the winter to reflect only the “car” crossing the line, not any part of it - and part of the wheel was now deemed to be OK. The judgement from the stewards made specific mention of the fact that the race directors’ event notes for the weekend had been copy-and-pasted from last year’s and therefore did not reflect the updated sporting code.

Fast forward to Saturday morning. The latest edition of the race directors’ event notes contains a revision to the pit-entry rules. They state: "Except in cases of force majeure, the crossing by any part of any wheel, in any direction, of the white line prior to the pit entry or of the painted area, between the pit entry and the track, by any driver who, in the opinion of the stewards, had committed to entering the pit lane is prohibited.”

So, the race directors' instructions to the drivers contradict the international sporting code. Again.

Image source, Formula 1 Twitter

With Sergio Perez dropped down to P13, several drivers now move up the order. George Russell has a chance to atone for his qualifying crash from the second row of the grid.

One driver who does already know where they will be starting tomorrow's Austrian Grand Prix, regardless of today's Sprint result, is Valtteri Bottas.

The Alfa Romeo driver will line up at the back of the field after taking a new internal combustion engine, turbo, MGU-H and MGU-K.

Image source, Getty Images

George Russell and Sergio Perez had a date with the stewards after qualifying on Friday.

Russell was noted for "entering the track without permission" following his Q3 crash in the Mercedes, while Perez was under investigation for exceeding track limits at Turn Eight in the Red Bull during Q2.

A warning was handed to Russell for "entering the track on foot" but for Perez, the punishment served was stronger.

The Mexican driver, who qualified in fourth, will start today's sprint race in 13th place, after all his Q3 lap times were deleted, so his best 'legal' lap time in Q2 was only good enough for that P13 position.