Reigning F1 champion Max Verstappen has dismissed Mercedes' latest innovation as the team attempts to steal a march on its rivals ahead of the new season.
Mercedes rolled out its W13 at the start of the second pre-season test in Bahrain with a car sporting virtually no sidepods as it has cleverly repackaged its cooling system.
The car has sparked a furore, with Red Bull team principal Christian Horner allegedly declaring the concept "illegal", only to later be surprised by his own comments.
Even Ross Brawn, F1's managing director motorsports whose department came up with the new aerodynamic regulations, conceded Mercedes' design was "very extreme" and would likely spark debate.
Asked if he was worried by the updated Mercedes, Verstappen said: "No, I'm not concerned.
"We can only focus on ourselves. I said this so many times last year, and we have to do it again this year, even if the cars look a bit different.
"There are so many unknown things, what we need to learn about, so I'm not worried at all."
Mercedes' "blood, sweat and tears" - Russell
If Mercedes has found a silver bullet, it could prove to be a game-changer over the opening few races as other teams attempt to catch up.
Assessing the innovation, Mercedes driver George Russell said: "I guess it looks interesting but it's not about how it looks it's about fast it goes. It obviously caught a few people's eyes this morning.
"From my side, I'm proud to be part of a team that's pushing innovation, and all this hard work, blood, sweat and tears going into something pretty spectacular being pulled off is pretty incredible.
"But as I said, it doesn't matter what it looks like. We need to see if it's fast on track."
Russell does not believe any team has the advantage at the moment. "As Max said, they've a few things coming," added the Briton.
"At the moment, Ferrari probably look globally the strongest. In every low-fuel run, consecutive laps, they look very solid.
"And if you look at their sidepods they are quite drastically different to what we have at Mercedes and what Max has at Red Bull.
"Time will tell next week. It truly is unknown for now."