Motorsport: The lengths Toro Rosso went to for Kiwi Brendon Hartley

A Toro Rosso bigwig has revealed the extreme lengths the team had to go through to hand Kiwi driver Brendon Hartley his Formula One debut at last weekend's US Grand Prix - including contravening several of the FIA's regulations.

Graham Watson, Toro Rosso's team manager, on Friday, lifted the lid on the dramatic build-up to Hartley's impressive maiden Grand Prix in Austin, Texas.

The 27-year-old Hartley finished 13th after starting the race in 19th position due to Toro Rosso' 25-grid spot penalty for installing a new power unit in his car.

According to Watson, the team had to move heaven and earth after the last-minute decision to replace Pierre Gasly with Hartley.

"I was sitting in the Dubai airport lounge at 4am on the way back from Japan when [team boss] Franz [Tost] asked me what I thought about Brendon Hartley driving," Watson told Herald motorsport writer Eric Thompson from Mexico City.

"I thought he was joking for a moment and I said I suppose so if that is what you want. Franz said there were two or three in the mix but Brendon was coming out on top.

"By the time I got back [team base] it had been confirmed and it just went mental from there."

Toro Rosso had to bend several of the FIA's strict rules, to make it happen, Watson admitted.

"There are so many regulations that stipulate certain time frames that you have to lodge paperwork and other stuff," he said.

"We contravened most of them and were so far outside the window of the amount of time it's supposed to take. We had to get a superlicence, which Brendon obviously got without any problem, then there was the contract recognition board where you have to lodge his contract which involves lawyers and then you have to let the FIA know.

"There were also all these little things to be done as well. We had to get branded overalls made, which normally take 20 days, but we needed them in less than a week.

"The manufacturer had a fit but came through. I then asked if Brendon had an F1 helmet; he didn't, just a sportscar one.

"We had to then contact Bell in New Zealand to get them to deliver a new one to Brendon's painter in Auckland, get it painted and then delivered to Austin. It arrived Thursday before the race.

'So there you go, there's a lot more to it than meets the eye."

Hartley was this week confirmed as a starter for the remainder of the season, starting with the Mexican Grand Prix on Monday (NZT).