The new McLaren team principal is facing a potentially troubled start to his tenure after recently taking up the role following Andreas Seidl's departure to become CEO of the Sauber Group.
Stella conceded at the launch of the car earlier this month that he was “not entirely happy” with the team's latest machinery.
CEO Zak Brown then offered further insight into his team's problems by declaring that “we know we set some goals for development, which we didn't hit”.
Brown added that going into next weekend's season-opening Bahrain Grand Prix the team would be “off of our projected targets”.
Both Brown and Stella are confident, however, of the upcoming development path that will allow it to compete again for fourth place in the constructors' championship.
Asked by Speedcafe whether there was a need for McLaren to be aggressive with its development target, Stella replied: “Being aggressive is required.
“And being aggressive, it can be intended from a timeline point of view, like you want to bring these upgrades as soon as possible, and also from a development rate point of view.
“We see that the game is incredibly competitive. I think Formula 1 gets more and more competitive every year in terms of how many teams now have the facilities, the equipment, the people to develop cars at a very high rate.
“So yes, we have to be aggressive.
“If we want to meet our objective of being a top-four car over the course of the season, we have to out-develop our competitors, so we do have to be aggressive.”
Will Piastri and Norris get out of Q1?
Throughout testing so far at the Bahrain International Circuit, the suspicion is that in missing its targets, McLaren has a car at the hands of Lando Norris and Oscar Piastri that may even struggle to get out of Q1 for the first few races until it can deploy its first major upgrade.
As to his realistic ambitions for the first three grands prix in Bahrain, Saudi Arabia and Australia, Stella said: “We will see again the midfield is very compact.
“This means that if you don't do a good enough job, even in setting up and maximising what you have, you may struggle to get out of Q1.
“At the same time, you might be a Q3 contender, so I think the fork is relatively open, relatively wide.
“When I'm talking about competitiveness, at the moment, I would say our objective through the season is to be a top-four car.
“At the moment, I would say we are not necessarily in this range.”