George Russell suggested Red Bull has not shown its true pace advantage this year because of fears Formula One will step in to slow them down.
The Mercedes driver's prediction of Red Bull winning all 23 races this year is still on, with the reigning world champions going three-from-three to kick off the season.
There are many examples of F1 stepping in with rule changes aimed at slowing a dominant car and Russell thinks Red Bull is wary of that happening again.
"For sure they're holding back," Russell said after retiring from Sunday's race.
"They're almost embarrassed to show their full potential because the faster they seem globally the more the sport is going to try and hold them back somehow.
"Realistically they probably have seventh-tenths advantage over the field. Max has no reason to be pushing it, nor has Red Bull.
"They've done a really great job, to be fair to them, can't take anything away. We clearly have to up our game."
Red Bull has looked to be in a class of its own this year.
Russell briefly led a Mercedes one-two at the Australian Grand Prix on Sunday as the former world champions showed a clear improvement on their sluggish start to the season.
A car failure took him out of contention, before Verstappen made light work of Russell's teammate Lewis Hamilton when he had the benefit of F1's Drag Reduction System (DRS) overtaking aid.
Red Bull already holds a 58 point lead over Aston Martin in the constructors' championship, with Mercedes a further nine points adrift.