The shield broke cover at Silverstone when it was fitted to Sebastian Vettel’s Ferrari in preparation for the Friday test.

The four-time world champ was expected to complete a short evaluation stint with the shield fitted at the start of the first practice session.

Formula 1 hopes to introduce the shield as a mandatory safety item as soon as next year.

The shield concept replaces the original cockpit protection device which originally had been planned to take effect this year, the controversial Halo device.