Nyck de Vries was sacked by AlphaTauri on Tuesday with the 34-year-old drafted in to take over the Dutchman's seat for the remainder of the current season.
Prior to the test, Ricciardo spoke of his excitement over returning to the F1 cockpit and had his helmet on well in advance in his latest LinkedIn post.
"#BritishGP was a blast as always... but my fun comes later today when I hit the track in the RB19 for Pirelli tyre testing. Vroom vroom," he wrote on the website.
The 34-year-old, who also represents Optus as the company's 'Chief of Optimism', is an eight-time grand prix winner with seven of those coming for Red Bull.
His two torrid years at McLaren saw him dropped a year early for Oscar Piastri, another Australian, but he did get one win for the Woking team, leading home a one-two finish with Lando Norris at the 2021 Italian GP.
A return to a full-time seat at AlphaTauri offers Ricciardo the perfect chance to resurrect his F1 career in a car that has struggled to perform this season.
AlphaTauri has two points after 10 races, both scored by Yuki Tsunoda, and Ricciardo will be aiming to significantly add to that tally in the remaining races.
Having no pressure to immediately win races or score podiums might be the stress-reliever Ricciardo needs to allow him to truly fall back in love with the sport.
When you consider the size of the Australian's vast fanbase too, there can be no doubt F1 is all the more richer for his presence on the grid.