Valtteri Bottas has warned a more serious incident was narrowly avoided when his Williams suffered damage in third free practice for the European Grand Prix due to a loose drain grate cover.

The Finn lost the entirety of the FP3 session after running over and kicking up a drain cover, causing enough damage to his Williams FW38 to necessitate lengthy repairs.

The second such incident in three races after Jenson Button suffered damage to his McLaren when Nico Rosberg kicked up a damaged manhole cover in Monaco, Bottas says it is 'unacceptable' to be having these issues, before pointing out the marshals nearby were lucky not to be struck.

"A drain cover came off as I entered the pit lane after just one lap and ripped through the right hand side of my car.

"That was game over for me, so I could only drive again in qualifying. What happened was unacceptable and could have been worse as the marshals standing on the pit wall were very lucky, as part of the drain cover just missed them by a whisker."

Bottas will start the Baku race from eighth on the grid after becoming embroiled in two identical incidents with Max Verstappen in qualifying when the Finn attempted to make a pass so as not to hinder his lap. On a weekend where Bottas has shown strong pace, he was frustrated that the FP3 damage and his compromised qualifying would prove a missed opportunity.

"We needed to run longer than usual in qualifying, to check the car and allow me to see how the track had evolved since yesterday, so we did two laps with that set of tyres, building my speed up and got reasonable laps in.

"I knew I could go quicker by a few tenths but I was just putting things together for Q3. The track was improving as well, so what I'm most disappointed is that I know we should have been fighting for the top three places, especially with what happened to Lewis and with P?rez's penalty."

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