Fernando Alonso and Stoffel Vandoorne only managed to qualify in 13th and 14th positions respectively, despite Alonso having shown top-10 form in FP3 on Saturday.

"Obviously it's a bit of a surprise, based on the pace we had in FP3," Boullier told Sky Sports F1 immediately after Q2. "There is a need for a big investigation.

"On his last lap Fernando found some pace in Sector 2 and Sector 3, which would have helped earlier. We need to find out what's going on.

"The balance is fine, obviously there's a lack of grip, that's my conclusion for the poor performance, but they don't report anything wrong."

McLaren scored a double points finish in the Melbourne season opener, which Alonso had started from a top-10 position.

"We were struggling last year in Bahrain as well, which is something we need to investigate for this layout," Boullier added.

"Our pace in Australia was not a dream, it was real in the race, and we know it will be better here tomorrow than the one-lap pace.

"But we need to find out why. We need to ask some questions at the factory.

"Like all of us on the pitwall, to be honest, I'm a bit astonished and we need to understand what happened."