Monday medical check reveals fracture for Aleix Espargaro
The title contender suffered the 160km/h accident in final practice, while trying the hardest rear tyre.
After being thrown into the air, Espargaro landed heavily on his right foot and was initially carried away on a stretcher before limping to a scooter and being taken to the Medical Centre.
But X-rays at the track found no fractures and the Spaniard was passed fit to continue.
Returning to qualify a brave sixth, Espargaro then rode to ninth in the race - just one place behind world championship leader Fabio Quartararo, whom Espargaro attempted to pass on the last lap.
Afterwards, the Aprilia star confirmed he would be seeking further scans in Barcelona, which have revealed the fracture to his right heel:
"Following medical checks carried out today at the Dexeus Hospital in Barcelona, Aleix Espargaró has been diagnosed with a heel fracture in his right foot," read an Aprilia statement.
"The Spanish rider, the victim of a frightening high-side during the last free practice session at Silverstone, then stoically took to the track for both qualifying and Sunday's race.
"The injury does not require surgical treatment, and Aleix has been prescribed seven days of absolute rest during which he will have to use crutches in order not to strain his injured foot.
"The aim is to arrive at the next race weekend (19-21 August, Austria) in the best physical condition."
Espargaro is 22 points behind Quartararo with eight rounds remaining.
Team-mate Maverick Vinales finished second to Francesco Bagnaia in Sunday's Silverstone race.
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