Felipe Massa may be scratching his head over one of his punctures in Bahrain, but Pirelli believes debris were to blame.
The Brazilian was forced to make an unscheduled pit stop on lap 17 due to a right-rear puncture and he was again forced to visit the pits on lap 37 with another tyre issue.
"The biggest problem was the punctures, which I think were two different reasons," the Ferrari driver said after the race. "The first was maybe delamination of the tyre, but the second was a puncture.
"I didn't touch anybody so I think it was debris. The first one it started vibrating a lot and then on the back straight, the vibration was so hard I had to get out of the throttle.
"The second one was a puncture. I got to the last corner, there was no tyre - no warning, it was just gone. This never happened to me before, two punctures in one race."
Pirelli motorsport director Paul Hembery, though, is convinced that debris caused the punctures.
"The first one we have got a big cut through the tread pack and the second one has a cut in the sidewall. We can see through the tread as there is a hole through the top of the tread as well," he told Autosport.
"Plus, one of them came back with a bag of carbon from another car, some very large pieces of carbon. It shows that there was quite a lot of debris out there."
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