During FP1, the only dry Friday session, Melbourne winner Carlos Sainz set the best time of the Ferrari duo during a short flurry of hot laps conducted on softs but was nonetheless 0.213s shy of Max Verstappen's headline effort.
In the meantime, Leclerc was eclipsed by both McLarens and stacked up sixth in the overall FP1 order, a quarter of a second away from his team-mate over his lap.
The Monegasque hoped that he would be able to unearth a "special lap" in Saturday's qualifying session to put his Ferrari on pole for the first time in 2024, but reckoned that Red Bull had the upper hand after the opening day of running.
"I'll do my best [to fight for pole]. This is the target for sure. But in order to do so we need to make sure that we are prepared in the best possible way for tomorrow," Leclerc said.
"And at the moment, I still feel like we are lacking a little bit of pace to go and challenge for pole position because Red Bull seems strong, and especially Max until now.
"There's still quite a bit of work to do. But if there's a special lap to be done, I hope I'll be the one to do it."
Sainz was more optimistic about Ferrari's chances, explaining that Ferrari had drawn closer than expected to Red Bull after the initial FP1 times were locked in.
He added that Red Bull would nonetheless provide a typically tough challenge, but was keen to point out the advancements that Ferrari had made towards the Milton Keynes squad compared to last year's race at Suzuka.
"Honestly, it's a bit closer to the Red Bulls than I anticipated or expected, so positive signs in terms of progress made from five months ago to now," the Spaniard enthused.
"It's still obviously FP1. You don't know what fuel loads and engine modes they're running. Obviously last year we were eight tenths off in quali, and here to be two tenths off in FP1 was a good feeling or a good starting base. But they're going to be difficult to beat."
Red Bull advisor Helmut Marko reckoned that Ferrari had shown up on Red Bull's radar through its FP1 pace, but hoped that the Italian outfit's pace had emerged through a lower-fuel run rather than on genuine merit.
The Austrian felt that Red Bull still needed to spend time on dialling in its Suzuka update, as the rain-affected FP2 had limited the team's data set on the revised sidepod inlets and floor that it brought to Japan.
"That Ferrari is pretty quick. But we hope, or we are sure, that they ran less fuel and a higher engine mode today than what we did," Marko noted.
"But they are still very tight to us. The long run was basically only three laps, but still those three laps from Leclerc were quite impressive.
"We have quite a big upgrade and for the first outing there wasn’t time for fine-tuning.
"I hope tomorrow we have some dry sessions, so we can really get the maximum out of the car. Hopefully we are ahead, in qualifying for sure, but also in the race."
