Piastri rocketed onto the grid in 2023 and quickly established himself as one of the brightest prospects.
He won the F1 Sprint in Qatar, having claimed pole for the 100km hit-out, and proved to be a challenge for team-mate Lando Norris.
Throughout the year, Piastri made few errors and endeared himself to the team with a deliberate, methodical, and controlled approach to race weekends.
And it is that which Stella is hoping will accelerate into 2024.
“I will shy away from results,” the McLaren boss told Speedcafe as part of the KTM Summer Grill.
“For me, that’s not the important element. For me, it’s more where do we need to improve?
“With Oscar, we have seen [in 2023] that we gained quite a lot of experience in the race.
“What happens in the race, you can’t really experience that in practice – you can a little bit in testing, but there’s no testing anymore in Formula 1 – because in the race you go for 20/25 laps in a row with the same set of tyres, and there’s a lot of your race pace and your race competitiveness that has to do with understanding how am I going to use my tyres? How do I perceive that the balance is evolving, and what does it mean in terms of compensations with my driving, with the tools that are available in the car, like controlling the differential, the engine braking, and so on.
“This is experience that Oscar has made in his first season in Formula 1, but we also have to think that from track to track, from event to event, this experience kind of never repeats itself.
“The amount of learning is enormous,” Stella added, “and this is where I see, with Oscar, we need to capitalise on what we learned in 2023, try to exploit that in 2024.
“It will be once again a bit of a journey of accruing this learning, making good use of it.
“Oscar, at his advantage is that he can use his brain power in a very effective way in capitalising this experience.”
Key to Piastri’s success in 2023 was his ability to remain cool under pressure.
Despite a year on the sidelines in 2022 and the bright spotlight of racing in Formula 1, the Melburnian maintained a mental state that impressed Stella.
It has led the Italian to compare Piastri to Michael Schumacher and Fernando Alonso, with whom he’d worked at Ferrari.
That was epitomised by the approach the Aussie adopted for race weekends, building up throughout practice before delivering when it mattered in qualifying.
“The other opportunity we have, for instance with Oscar, is try to be… he can be quick, he builds on it through the weekend,” Stella said.
“The sooner we get quick in a weekend, as much as possible, the more we can move on to other tasks so that we can be as prepared as possible come the race.
“So using the speed earlier in practice will put him a little bit on the front foot compared to now, where it takes a couple of sessions, or three, to get to the ultimate speed.
“So there’s so much that we can do,” Stella surmised.
“That’s our focus. If we do that, you will see that results will come to us.”
McLaren has not yet announced its 2024 season launch plans though is set to join the other nine teams for three days of pre-season testing in Bahrain next month.
The opening round of the year takes place at the same venue, from February 29-March 2.