Kimi Antonelli put Mercedes on top at Zandvoort during Friday's sole practice session for the Dutch Grand Prix, but the real talking point was what went wrong for Red Bull. The reigning champions are clearly struggling with their current setup, and it's raising some serious questions heading into the weekend at one of Max Verstappen's home tracks. Antonelli's pace was solid throughout the session, showing that Mercedes have got the car balanced nicely for the challenges of this quick circuit.

More F1 news: Antonelli Tops FP1 at Zandvoort as Ferrari Bring Fresh Upgrades to Dutch GP

Red Bull's troubles weren't just about missing out on the top time. The team seemed to be hunting for answers on multiple fronts, trying to get their car happy on the challenging Zandvoort layout. With upgrades being thrown at this weekend by several teams, Red Bull's relative struggles stand out even more. It's the kind of session where you see the field is genuinely mixing it up, and the traditional hierarchy isn't quite holding as firm as usual.

More F1 news: Antonelli Leads the Way at Zandvoort as Lawson Impresses in Surprise Red Bull Drive

The Friday practice at Zandvoort matters because it's the only dry running before teams go into qualifying and the race. Every lap counts when you've got limited track time. Antonelli capitalizing on these opportunities shows why Mercedes brought him along this season. He's not just sitting around waiting for a setup to hand him the lap time, he's actually extracting everything from the car.

More F1 news: Antonelli Quickest in Wet to Dry Zandvoort Friday as Mercedes Leads the Way

Teams arrived at Zandvoort with serious upgrade packages to gain an edge, and the Friday running gave them their first real look at how effective those changes are. Red Bull not being where they'd normally expect to be at this stage could be down to setup sensitivity, or it might be that their current direction isn't quite working for this particular track. Either way, they've got some serious work to do before Saturday qualifying if they want to sort out what's clearly bothering them.

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