Oscar Piastri believes his year away from racing has only made him hungrier to finally burst back into action and fulfil his long-held dream of becoming a Formula One driver.

Talking on the eve of race weekend at the Bahrain Grand Prix on Thursday, McLaren's much-touted Australian rookie admitted that his F1 debut would be the culmination of a dream he's had since starting as a nine-year-old boy racer.

"It's been about 12 years since I started racing, so everything I've done up to this point has led to now," mused the 21-year-old from Melbourne.

"To be calling myself a Formula One driver and be preparing for my first race is a special feeling, definitely."

Piastri, the only Australian on the grid after he replaced his compatriot Daniel Ricciardo at British-based giants McLaren, enters his debut race with a glittering junior CV but some ring rust after having not raced at all in 2022 when he was reserve at Alpine.

"Having that year out, I definitely gained a new-found appreciation for how much I enjoy going racing," he said.

"Even in the bad times, it's still better to have those bad times than have no times at all, I learned.

"I did some testing last year, quite a lot of testing by myself on the track, but it's obviously not the same as having other people around you.

"I did a bit of sim racing at home, but it's hard to replicate the real thing without going racing.

"So I think I've come back with probably more hunger than previously and now that we're here on the grid, it's just a great feeling. I'm looking forward to getting stuck in."

Expectations of Piastri, who's been called "extremely gifted" by McLaren's team principal Andrea Stella, have been tempered only because of the team's evident pre-season problems.

"Obviously, the test (last week's pre-season session in Bahrain) wasn't the smoothest, but I think we'll get a better understanding of where we're at come tomorrow. I think we're somewhere in the midfield," said Piastri.

But even though McLaren set the alarm bells ringing about their prospects when CEO Zak Brown said last week the team hadn't met its development targets, Piastri's teammate Lando Norris offered up a more positive assessment on Thursday.

"I don't think we're in a terrible place as it is," said the Briton.

"We're maybe not as strong as we want to be, but we're also maybe not as bad as what some people are expecting. We have some good things in the pipeline ... it's a long season."

Talking at the same news conference as Piastri was 41-year-old veteran Fernando Alonso, who'll be making his 356th F1 start while the Aussie is on debut - but both feel privileged to be racing each other.

Aston Martin's Alonso's debut was at the Australian Grand Prix in Melbourne on March 4, 2001, while Piastri was born in the same city just a month later.

"It's a privilege to race against Fernando, obviously. I grew up watching him. My first go-kart ever was a Fernando Alonso kart, actually," smiled Piastri.

"On paper, it sounds a little bit strange... for Fernando's career to be longer than I've been alive, but it's a big privilege to race against someone like him."