Upon hearing that his stray wheel had hit 'Big Nige', one of his former Williams truckies, Mercedes driver Nico Rosberg joked that the wheel would have come off worst.

The scary incident occurred on lap 16 of Sunday's Hungarian Grand Prix, when a problem with the nut on the right rear wheel of Rosberg's car sent the wheel bouncing down pit lane as the young German pulled away from his stop.

The wheel eventually hit Williams mechanic Nigel Hope, who underwent a precautionary visit to the medical centre before resuming his duties as part of the pitcrew.

"After I heard that my tyre hit 'Big Nige', one of my old Williams truckies, I was more concerned about my tyre than him!" joked Rosberg. "But seriously, it's great that he doesn't have any serious injures and I'm sorry for the incident."

Mercedes were fined $50,000 for the dangerous incident. Team principal Ross Brawn said Mercedes will now investigate why it happened and report their findings to the FIA.

"We had a problem with the right rear wheel during Nico's stop and his car was sent without the wheel nut being properly fitted," said Brawn.

"We will have a thorough investigation into the incident and report our conclusions to the FIA.

"We are thankful that no serious harm was caused by the stray wheel and send our best wishes to the Williams mechanic who was unfortunately injured," Brawn added.

"Thankfully the mechanic who was hit by the tyre was quickly released from his check-up in the medical centre and our apologies to him and the Williams team," stated vice-president of Mercedes motorsport Norbert Haug .