Gavin runs with Button in a spin.

The Mild Seven Renault F1 Team experienced a disrupted second day of testing at Silverstone, and was forced to call on the services of third driver Oliver Gavin to complete the programme set out for one of its two cars.

After experiencing dizziness during the morning, Jenson Button was replaced for the afternoon session by fellow Briton Gavin, who completed a programme of software development on the leading R202.

The former British F3 champion was only at Silverstone to show a few corporate guests around behind the scenes of testing, and was looking forward to a relatively easy day before he got the call from Renault. He initially completed a five lap stint and then took the car out again several times during the session.

"I just happened to be at Silverstone with Walnut Motorsport and, when the team asked me if I would continue Jenson's programme, I was surprised and delighted," he said, "I hope Jenson feels better soon, but I guess I was just in the right place at the right time!"

The second car, piloted by regular test driver Fernando Alonso, was used to conduct a wheel comparison during the morning session, before spending the afternoon evaluating engine modifications ahead of next weekend's USGP at Indianapolis. The Spaniard ended the day third fastest overall, with Button edging Gavin for fourth.

"It was a strange, slightly disrupted day, but Oliver worked well today and will continue in the car tomorrow so that Jenson can recover fully before leaving for the US," commented technical director Mike Gascoyne.

Gavin will continue with the software development programme today [Thursday], driving alongside Alonso, who expects to complete a race distance as well as a tyre programme for Michelin.