"I'm trying not to put too many expectations on my F1 debut, but I feel ready for it".
He was released form their young driver programme in July 2010, going on to unsuccessfully trial for the Mercedes two years later before finding a home in endurance racing.
He has raced in the Le Mans 24 Hours each year since, while also competing in the FIA World Endurance Championship since 2014. On Friday, the team confirmed he will do the latter, giving Hartley a remarkable opportunity at a Formula One debut.
With Carlos Sainz moving to Renault and Gasly returning to Japan to race in the final round of the Super Formula series, the Faenza-based outfit is bringing back Dany Kvyat but still has a seat on offer for Austin.
The 27-year-old was rumoured to be in talks with the Italian F1 team but complications around his availability were also being factored in until the team announced this morning they had signed Hartley for the race.
Hartley says the years he missed out on F1 made him more determined to make this opportunity a reality. However, fellow Red Bull junior Alguersuari won the title and would step up to a Toro Rosso drive mid-way through the following season.
Speaking to ESPN during winter testing this season, Ricciardo said he rated Hartley as one of his toughest opponents in the early days of his Red Bull career and even credits the Kiwi as one of the reasons he was able to overcome homesickness after his initial move to Europe from Australia.
And while it might seem likely that Kvyat will stay on, he has now been demoted twice by Red Bull - once from the senior team back to Toro Rosso in May 2016 and then dropped altogether after this year's Singapore event.
It seems, though, that a decision has been made, as Toro Rosso team principal Franz Tost is now looking for another driver to fill Gasly's seat.
"We are really happy to have him back in our team". With Carlos Sainz departing to Renault, the team looks set to hand a full-time role to Gasly, who impressed in Malaysia and Japan, but the team has doubts about Kvyat, who has endured a hard time since being demoted from Red Bull in 2016.
"I'm convinced he'll do a fantastic job for us".