Disappointed Bottas says Williams cannot afford to make any more mistakes

A rotten week for Valtteri Bottas ended very disappointingly in Spa and the Finn says Williams can’t afford any more mistakes for the remainder of the Formula 1 season. The British team was forced to apologise to its driver for fitting a mixed-up set of tyres at a pitstop during the Belgian Grand Prix.

It followed the end of Ferrari's interest in Bottas, as the Maranello team re-signed Kimi Raikkonen for 2016, with Bottas admitting he hadn't done enough this season to impress the Italians.

After qualifying a season-best third in Spa, Bottas had been in the fight the for the final podium place during the Grand Prix , but after a poor getaway from the grid that dropped him from third to sixth, his afternoon was further compromised by Williams fitting a set of soft tyres at his first pitstop that mistakenly included a medium compound Pirelli.

The Finnish driver was awarded a drive through penalty and eventually finished the race in the ninth place.

Bottas said: “We can't afford mistakes like this. We definitely didn't get 100 per cent out of the weekend. We just didn't have the pace to challenge the guys in front. But we should have got more points than what we did."

Speaking to TV crews after the race, Williams’ head of vehicle performance, Rob Smedley, admitted the team needed apologise to Bottas for the tyre mix up and avoid blaming any individuals for the incident.

He said: "There are two things we should do: the first is apologise to Valtteri because obviously we absolutely ruined his race as he was there with Sebastian [Vettel] and [Romain] Grosjean before that happened.

"Secondly, what we shouldn't do is blame individuals. We need to go away as a group of people and look at what happened."

There are two ways that this error could have happened. One is that the tyres were incorrectly placed in tyre blankets at the outset so that the rogue tyre in the set was not spotted.

Another is that teams have sets on racks primed for use at various stages of the race, depending on emergency scenarios, like a Safety Car. All sets are numbered and when the command was given to grab a set ready for Bottas' stop one of the mechanics may have heard wrongly and grabbed a tyre from a set number he thought he heard rather than what was requested.

Top teams report that they have two or three failsafes to avoid this kind of error happening, since Ferrari did it in 1999 on Eddie Irvine's car it has been a rare occurrence. Although they realised the mistake and the car didn't leave the pits.

Williams is currently third in the constructors’ championship, 81 points behind Ferrari in second place and just 53 points ahead of Red Bull in third. As well as avoiding any more operational mistakes, the Grove based squad will need to repeat the impressive development rate it produced in 2014 if it is to finish in third position in the constructors’ standings again this season.

Williams’ technical director, Pat Symonds, recently told Autosport that the team did have more upgrades to add to its 2015 car throughout the remaining races of the season.

He said: “We have plenty to come yet and have plenty already sitting in the pipeline which has been signed off and is just going through the final bits and pieces.

"There is still windtunnel time allocated and there is still work going on in vehicle dynamics.”

Williams know they cannot afford to make any more operational errors at power dependent tracks like Spa that play to the strength of its Mercedes power unit. The team is also braced for a difficult weekend in Singapore where the slow-speed, high-downforce nature of the track could see it suffer like it did at similar circuits at Budapest and Monaco.

Ferrari have produced the second quickest car this season and look to have second place in the constructors’ championship sealed, but will Williams will have a battle with a resurgent Red Bull to hold onto third place.