Red Bull's ongoing struggles have shown that the gap between the championship leaders and their rivals is shrinking, according to one of Ferrari's star drivers.
The reigning constructors' champions continue to lead the way in 2024, but their status as Formula 1's dominant force has looked increasingly vulnerable in recent weeks.
Verstappen then endured a miserable weekend in Monaco, finishing sixth on Sunday after a poor qualifying session the previous day.
His team-mate, Sergio Perez, has also seen a sharp drop-off in form, failing to feature on the podium in his last three races.
A 'tight fight' at the top
Given that Red Bull delivered wins in all but one race during 2023, their performances this season haven't lived up to the team's lofty expectations.
Speaking after the Monaco Grand Prix - won by home favourite Charles Leclerc - Ferrari's Carlos Sainz admitted that while the Milton Keynes-based outfit remain the team to beat, the chasing pack now have renewed hope that they can provide a substantial challenge.
"I think my common sense tells me that on normal tracks Red Bull should still be favourites," said the Spaniard, as reported by FIA.
"Domination, like we were seeing, hopefully not. But favourites, yes.
"And then it will be a very tight fight with both McLaren and us - I think we are all three at a very similar level.
"Our last reference of a normal track is Imola and Miami, and if I see those two tracks, we seem to be half a tenth behind McLaren and maybe a tenth or two behind Red Bull.
"It still means that that any small progress, any small upgrade, any small thing that we bring to the car, might switch it to a potential race victory or a winning car."