Pirelli discovered damage on other tyres over the Belgian Grand Prix weekend, as it still seeks a definite answer as to what caused the Nico Rosberg and Sebastian Vettel tyre failures.
Rosberg suffered a tyre blowout in Friday practice, which was believed to have been caused by either a piece of debris or a car part rubbing on the tyre.
However, despite extensive checks, no piece of debris could be found – and an attempt by Mercedes to check its floor – using blue paint along the floor edge that was suspected (pictured above) – did not find anything wrong with its design.
In the race, Vettel's tyre failed on the penultimate lap, but again there was no confirmed answer from Pirelli about why it let go in such a way.
Pirelli suspected it was related to high wear – with the tyre having done 28 laps – but it is understood there was no evidence of lower temperatures or performance drop-off that would have have pre-empted such an event.
Sources have now revealed that Rosberg and Vettel were not the only drivers to face tyre problems at Spa-Francorchamps, with cuts being found in several other tyres over the weekend after practice sessions.
Had these cuts manifested themselves in the race, then there was a chance that they have could led to bigger problems similar to what Rosberg suffered.
It is understood these were mainly appearing on the rear tyres, although Pirelli could not find what was causing the damage.
However, it wrote to the FIA to ask for extra precautions to be taken in ensuring the track surface – and run-off areas – were cleaned extensively before the grand prix.
It is also understood that teams contacted the FIA to also express their concerns about potential debris around the track.
One theory is that because drivers were taking liberties in some run-off areas, especially at the top of Eau Rouge, that they could have been running over debris from previous incidents.
But although Vettel was seen running slightly wide across the kerb at Raidillon moments before his tyre failed, Pirelli is still convinced his failure was totally wear related.
When asked if there were any similarities between the two right rear tyre failures, Hembery said: "No. Rosberg was an external cut, this was pure wear.
"If you look at the images, the carcass was still intact so it was a wear issue, the second one on Friday was a cut."