Red Bull motorsport advisor Helmut Marko has suggested rival Mercedes has taken a "step backwards" with its W14.
The Silver Arrows secured only one victory with the W13 last season as F1's new technical regulations hit hard - Mercedes struggling with drag efficiency issues as well as excessive porpoising.
There was optimism that the second season of the regulations would allow the German manufacturer to get on top of the problems that plagued its 2022 campaign but all hope seemed to vanish at the season-opening Bahrain Grand Prix.
READ MORE: Verstappen suggests wins 'on the table' for Alonso this year
Lewis Hamilton finished fifth and George Russell seventh, with the former finishing 51 seconds behind race winner Max Verstappen.
Team principal Toto Wolff alarmingly suggested Mercedes would ditch its radical zeropod concept after qualifying, such was the gulf to Red Bull - as well as the Aston Martins bettering the W14.
Mercedes facing obstacles
Red Bull had cited Mercedes as its closest rival ahead of the season start but assessing the Brackley-based team's fortunes after the first round, Marko told OE24: "Mercedes has more than one obstacle, that's clear.
"They have not made any progress compared to last season. If you look at the gaps, it was even a step backwards.
"They seem to have lost their way somewhere. I am curious to see what they will do now. Because of the cost cap, it's such a problem to develop the car routinely.
"How do you put together a completely new car? Unless they make the golden shot, which I wouldn't assume after recent experiences."
READ MORE: F1 Power Rankings: Full driver order revealed after Bahrain GP