Image source, Getty Images

F1 journalist Dan Knutson in Barcelona: "This has been a common sight during the eight days of pre-season testing - an empty Mercedes garage while either Nico Rosberg or Lewis Hamilton is out on track racking up the laps in the reliable W06."

Fernando Alonso and Romain Grosjean make a brief appearance on the circuit, both on mediums, before heading back into the pits. Sebastian Vettel also heads in as his times on the softs begin to tail off, leaving Valtteri Bottas alone on the circuit.

Image source, Mercedes

Nico Rosberg brings up his half century of laps as Sebastian Vettel and Carlos Sainz rejoin him on the circuit.

Meanwhile, Daniil Kvyat is improving, his latest effort in the Red Bull a 1:29.982.

Andrew Benson
Chief F1 writer

"It has been a low-key winter for Williams so far, with few attention-grabbing lap times, even if Felipe Massa was third fastest on Friday at this test. But there is a quiet confidence that they will have a strong season.

"Valtteri Bottas, who continues in the car this morning after taking over from Massa at lunchtime on Saturday, said: 'I think it's going to be close this year. It is clear Ferrari have improved and possibly Red Bull. We have, and Mercedes is going to be strong again. But I think it is going to be close. We will be there or thereabouts.'"

Image source, Williams

Williams:, external A few changes and Valtteri Bottas heads back out. So far he has done 36 laps.

Nico Rosberg is back on the circuit, with Sebastian Vettel and Carlos Sainz returning to the pits after that short stint. Rosberg, on medium tyres, improves with a 1:26.782 but remains third fastest.

Force India:, external As we hit noon in Spain, Nico has completed 26 laps with a best of 1:27.561. The Hulk is back in the car, ready for his next run.

Image source, Toro Rosso

Toro Rosso:, external A stop in the sun...

Image source, Chris Akrill

Chris Akrill:, external There's plenty of people here, we're all in the sun!

Carlos Sainz is also out on the circuit and, like Sebastian Vettel, is running on soft tyres. He knocks Vettel off top spot with a 1:25.684.

Sebastian Vettel is out on softs and he clocks the fastest time of the day so far, a 1:26.454.

So far so good for the patched-up McLaren and Fernando Alonso, with the new fix applied to their faulty seal seemingly doing the business this morning. Alonso is not on the circuit at the moment, with Sebastian Vettel's Ferrari providing the only on-circuit activity.

Quiet again in Barcelona with everyone back in the pits. Mercedes continue to tick over the mileage clock with Nico Rosberg having got 46 laps under his belt this morning.

Matthew Mc20nnell:, external Will be great to see McLaren's pace in Australia once they've turned the engine up.

Fernando Alonso is back out and putting some good laps in. He improves with a 1:28.308 as he takes his lap count into double figures.

1. Nico Rosberg (Mercedes) 1:27.142 (38 laps)

2. Carlos Sainz (Toro Rosso) 1:27.236 (45 laps)

3. Sebastian Vettel (Ferrari) 1:27.238 (31 laps)

4. Romain Grosjean (Lotus) 1:28.029 (23 laps)

5. Valtteri Bottas (Williams) 1:28.171 (27 laps)

6. Fernando Alonso (McLaren) 1:28.308 (10 laps)

7. Nico Hülkenberg (Force India) 1:28.764 (22 laps)

8. Daniil Kvyat (Red Bull) 1:34.031 (26 laps)

9. Felipe Nasr (Sauber) No time (3 laps)

Mark Jones:, external McLaren car and Honda engine will be strong once reliability sorted. I can see McLaren getting podiums this year.

Image source, McLaren

McLaren:, external And we're away. Fernando takes the MP4-30 for a spin in the Barca sun.

A tenth of a second separates the top three as Nico Rosberg goes fastest with a 1:27.142, putting him just ahead of Carlos Sainz.

F1 journalist Dan Knutson in Barcelona: "There were more fans in the grandstand but they drifted away after getting bored waiting for Fernando Alonso to appear in the McLaren-Honda. The fact that Alonso will only drive for half the day, and that the car has completed so few laps over the past three days no doubt kept other fans at home."