Red Bull Team Principal Christian Horner knows that his team have some issues to work out ahead of qualifying for the Dutch Grand Prix, after an FP2 session that saw them finish well behind the leaders.
Max Verstappen clocked the fifth-fastest time, after being hampered by a red flag, while Sergio Perez finished outside the top 10 as the Ferrari duo of Charles Leclerc and Carlos Sainz took the top two spots.
When asked about his overall feelings heading into Saturday at Zandvoort, Horner admitted that the Scuderia look impressive.
"They certainly look quick," Horner told Sky Sports. "I mean Ferrari, in particular, [with] both cars up there.
"We didn't get that first lap, so we're not quite sure what our ultimate pace is, but we have got a few issues to deal with.
"The car was a lot happier on the long run. Max was putting in some good times. Sergio's pace improved quite significantly as well, so I think we have just got a bit of tidying up to do for the single lap. But of course, you've gotta get a clean lap."
Drivers will be pushing to take pole position in qualifying on Saturday, with Horner pointing out that traffic could play a big role in who starts at the front.
"Drivers raced here in Formula 3, on their way up into Formula 1," Horner added. "Max, I don't think he raced here in Formula 3, but he's done a few laps around here.
"It's a good little circuit, it's just traffic is gonna be a premium in qualifying, because it's a short lap and a lot of corners. It's difficult to get out of the way as well."
Video: The secrets of the the new Zandvoort F1 circuit
Follow Rudy van Buren as he takes you on a flying lap around the home of the Dutch Grand Prix at Zandvoort.