Williams apologised to Valtteri Bottas on Sunday for the botched tyre-change that ruined his hopes of a possible top five finish in the Belgian Grand Prix.

The Finn had to take a drive-through penalty after the team fitted the wrong tyre to his right rear wheel at a pit stop.

He drove out to continue racing with three ‘softs’ and one ‘medium’ tyre, an infringement that cost him.

"There are two things we should do," said head of vehicle performance Rob Smedley.

"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."

Bottas said he had never heard of such an incident before.

"It's very disappointing," said the 25-year-old.

"I've never heard of anything like this happening, but what can you do?

"For sure that cost us a lot. Looking at the times in the end without that penalty we might have been fifth or something as I was at the front of that pack.

"But our pace was not enough to be top three, which was our aim, so it was not our day."
Source: AFP