Mercedes was stunned by size of debris in Bottas’ car

Mercedes says it “couldn’t quite believe” the size of the debris that lodged itself under Valtteri Bottas’ W11 at Formula 1’s Emilia Romagna Grand Prix.

Bottas led away from pole position but on lap two ran over a large chunk of the front wing endplate that had fallen from Sebastian Vettel’s Ferrari following a clash with Haas’ Kevin Magnussen.

Bottas remained ahead but later ceded position to team-mate Lewis Hamilton through the pit stop phase and subsequently ran wide through Rivazza corner.

Bottas dropped to third, behind Max Verstappen, but re-took the position when the Red Bull driver suffered a tyre failure.

Mercedes removed the debris at Bottas’ second stop, which came during the Safety Car period caused by Verstappen’s exit, and communicated a photo (above) to show the size of the piece.

“We were having a conversation relatively early on in the pace that we were seeing a big drop in performance,” said Mercedes’ trackside engineering director Andrew Shovlin.

“In terms of lap time it was seven or eight tenths of a second [per lap], we weren’t really believing the sensors because we were looking at how Valtteri was not pushing particularly hard, able to do reasonable lap times, and could build a bit of a gap.

“Early on we couldn’t quite believe how big it was and we didn’t quite know what it was.

“I think because when you look at the size of it and the fact it’s red you can’t believe that we couldn’t see it on the cameras but it was lodged in the black area and because the whole car is black there we couldn’t see that.

“If we could have seen where it was we could have possibly do a more effective job of getting it out at the first stop.

“He did the right decision to go right over it as taking it over a tyre would very lucky have been an instant puncture but through not fault of his own it basically held him back for the whole afternoon.”