Martin Whitmarsh concedes that in hindsight McLaren should have put Sergio Perez on the intermediate tyres during Q2 for the Australian GP.
Perez failed to make the cut after a decision to swap to the supersoft slick tyres cost him dearly.
But while team-mate Jenson Button quickly changed back to inters - the better choice on the still damp track - Perez pitted for a second set of slicks.
He finished down in 15th place while Button progressed to Q3, claiming tenth for Sunday's season-opener.
"I think first we took a risk with Sergio going on to a dry tyre," Whitmarsh told Sky Sports F1.
"It was a very difficult call, I think clearly sector one, sector two, it was quicker on the dry tyre, sector three was still struggling on a dry tyre, but we took that risk," Whitmarsh confessed.
"Unfortunately there was some issue on that set of tyres - he thought it was a puncture - so we had to change so that put us on the back foot. With hindsight I think we should have switched back to the intermediate tyre, but we didn't.
"So that was a shame, it didn't come off for us, and it means that took us out of Q3 with Sergio."
