Bottas problempublished at 13:35 Greenwich Mean Time 26 February 2019

13:35 GMT 26 February 2019

Valtteri Bottas has just got out of the pits for his first lap. But wait just a minute, wait just a minute. He's stopped at the side of the track by Turn Three! Red flag.

And one of those quick red cars is out on the track as Sebastian Vettel gets involved for the first time today.

Mercedes say the changes they have made to their car today were all "pre-planned" and "part of the usual development race".

Chris Medland
F1 journalist in Barcelona

It has been a slow start after lunch with only George Russell getting some laps in so far. McLaren weren’t seen after Lando Norris stopped on track in the morning session, but should be able to get back to work pretty soon according to the team.

The stoppage was “caused by a loss of hydraulic pressure”, the team say. Teams often stop the cars for precautionary reasons and investigate during testing - the main goal obviously being to iron out those weaknesses by the time racing starts in Melbourne.

As we're talking about Lando, have a look at this video as he talks about his journey to Formula 1 from karting when he was only eight and how he failed the theory part of his driving test first time around.

The video was made before the end of last season if you're wondering why he is talking about Lewis Hamilton being a four-time world champion.

Enjoy.

A message reaching us from McLaren, who say: "Lando's stoppage was caused by a loss of hydraulic pressure, we should be back out soon."

Just George Russell out there at the moment, he has the track to himself.

George Russell is the first out there. He's sixth fastest so far today and his team certainly need a lot of track time after going AWOL for the opening two days.

The afternoon session is under way. Three changes for you. Valtteri Bottas is now in the Mercedes, Sebastian Vettel in the Ferrari and Daniel Ricciardo in the Renault.

Well, they will be when they get out there.

No movement from anyone, still finishing off their lunch perhaps?

I haven't got too much to say about F1 testing so far either but have managed to get through five hours worth of waffle (minus a quick snack, of course).

We saw Stoffel Vandoorne lurking around in Barcelona earlier on, and now his 2018 McLaren team-mate Fernando Alonso is here too.

Just joining us? Where have you been? Antonio Giovinazzi was the quickest, ahead of the Red Bull of Pierre Gasly and the Ferrari of Charles Leclerc, although the Italian was on the softest tyres of those three.

And we're fed and back. Shall we go again?

And live text commentators need their food as well or they get stroppy. So I'll be back in 30 minutes or so, with the afternoon session beginning at 13:00 GMT.

The F1 timing app said Lewis Hamilton had been out for 83 laps, Mercedes say 96. No matter what, that's a good stint and an awful lot of information.

Williams are happy with George Russell's efforts. Remember, this is day five of testing for everyone else, but only day three for them after completely missing the opening two days.

1. Antonio Giovinazzi (Alfa Romeo, 1:18.589, 56 laps)
2. Pierre Gasly (Red Bull, 1:18.647, 61 laps)
3. Charles Leclerc (Ferrari, 1:18.651, 29 laps)
4. Lance Stroll (Racing Point, 1:19.139, 44 laps)
5. Kevin Magnussen (Haas, 1:19.644, 84 laps)
6. George Russell (Williams, 1:19.662, 46 laps)
7. Alexander Albon (Toro Rosso, 1:19.689, 39 laps)
8. Lewis Hamilton (Mercedes, 1:20.332, 83 laps)
9. Nico Hulkenberg (Renault, 1:20.348, 80 laps)
10. Lando Norris (McLaren, 1:22.306, 38 laps)

Tyres: Giovinazzi's best lap came on the C4 tyres, the second softest of the options, all of the others were on the C3 mediums, apart from Stroll (development tyre), and Magnussen and Hamilton (both C2 - the second hardest tyres).