Felipe Massa's Williams F1 car missing parts after Canada crash

Massa crashed heavily under braking for Turn 1 during the first practice session for this weekend's Montreal F1 race, after the drag reduction system on his car's rear wing failed to close correctly.

Williams rebuilt his car in time for the second practice session and he went on to qualify eighth for the race, less than a tenth behind team-mate Valtteri Bottas.

Massa reckoned he would have been ahead had Williams been able to rebuild his car to the same specification as before.

"With the issues we had in practice I didn't have everything in terms of parts in the car, so I was missing quite a bit of performance," said Massa, who estimated the deficit was "at least two tenths".

Williams performance chief Rob Smedley confirmed Massa suffered a performance deficit as a legacy of his earlier accident.

"We were short of parts after the accident," Smedley said.

"It wasn't possible to furnish his car with all of those parts and they add up to roundabout two tenths."

Williams spent part of Friday investigating the cause of the DRS fault, which Smedley said was related to the mechanism that controls it.

"It hadn't got enough hydraulic authority until the vehicle speed reduced to a certain value," he explained.

"There are some quite big bumps braking for Turn 1, and that just caught him out as he was building up during that first run and braking later.

"We hadn't seen it in the telemetry up to that point, so it caught us out as well.

"It was an unfortunate set of circumstances. After FP1 we sat down and tried to understand what the problem was.

"We understood it fairly quickly and rectified it, and thankfully haven't had any more issues this weekend."