The Suzuka weekend has unfolded unusually, with FP2 effectively being washed out by drizzle, which meant the teams spent most of FP3 on Saturday morning concentrating on long-run data gathering, rather than the typical qualifying simulation efforts.
In these, Verstappen trailed his team-mate Sergio Perez by an average of 0.122 seconds each time, while both were trumped by Ferrari's Charles Leclerc on a similar stint-length to the tune of a 0.482s average advantage using the medium tyres that are expected to be the key compound for race strategy.
Verstappen ultimately beat Perez to pole in Suzuka qualifying, while Leclerc could only manage eighth, four spots behind Carlos Sainz in the other SF-23.
When asked by Motorsport.com if he was surprised to see Ferrari fall from the pole fight it has engaged Red Bull in at the previous early 2024 rounds, Verstappen replied: "I cannot look inside the Ferrari garage [and say] why that is.
"But, it's quite obvious that in the long run, they seem quite competitive. So, we'll see tomorrow why that is or if it actually is the case like that.
"From our side, I have some ideas of what we have to look into to make tomorrow better and that's what we already changed [on car set-up] after FP3.
'So, hopefully that will be better for tomorrow. Our race pace is still not too bad, but it's not how I have been feeling in some of the races this year and last year. As comfortable, let's say like that.
"But, hopefully with the changes that we made it will be better."
Verstappen said he also felt McLaren looked "quite decent" on long-run potential at Suzuka and added that he was "just not very happy with myself – with how my long run was" in FP3, where he complained about an understeer balance aboard his RB20.
"So, naturally, everyone else looks a bit better," he continued.
Verstappen also stated that his apparent struggles on long-run pace left "a question mark going into [the race] tomorrow".
He added: "Especially [concerning] Ferrari – they look very comfortable.
"Maybe they were not so quick over one lap today, but they were definitely fast in the long runs. So, we'll have to wait and see how that will unfold tomorrow in the race."
But Sainz insists Ferrari's long runs – which Red Bull has been concerned about since FP1 on Friday morning – "are not better" when the caveats concerning engine modes and fuel loads are taken into account.
"It's just, I think, probably we are a bit lighter," Sainz added. "They always run really slow on Fridays, it always looks like we are gonna beat them on Sunday, and then they put 20 seconds on us.
"They are always super quick on Sundays and I think they sandbag a bit on the long runs because they know it's their strength.
"Maybe we're a bit closer [compared to 2023 where the lead Ferrari driver, Leclerc, finished 44s adrift in Verstappen's Suzuka victory], but it's still... it's not like we're gonna find half a second tomorrow in terms of pace."
