BAKU, Azerbaijan (AP) — Mercedes is slow again on a street circuit, and Lewis Hamilton can't understand why.

The seven-time Formula One champion was a second off the pace of Red Bull driver Sergio Perez on Friday and nearly as far adrift of standings leader Max Verstappen. Even making the top 10 qualifying shootout on Saturday could be a challenge.

With a lack of pace at the last race in Monaco, Hamilton was never in contention and dropped behind Verstappen in the standings. Baku is a street circuit like Monaco but presents a very different challenge with a long straight section along the seafront making top speed important.

Perez set a time of 1 minute, 42.115 seconds in the second practice to lead Verstappen by .101 after the Dutch driver had been fastest in the first session.

“Performance-wise, I think we had a great start to the weekend here in Baku," Verstappen said. "It was quite windy out there today, which wasn't easy for any of us, but it definitely makes things more interesting."

In Saturday's qualifying, Verstappen will be aiming for his first pole position since the season opener in Bahrain in March.

Mercedes, meanwhile, could only manage 11th for Hamilton and 16th for Valtteri Bottas.

“I don’t know where all the time is,” Hamilton told his team over the radio.

“We're definitely quite a chunk down and I think everyone will be scratching their heads and looking into the data, trying to figure out how we could improve," the defending champion said later. “The car is limited. There's areas where I should just be quicker but there's just no more grip."

Hamilton was slower than the Red Bulls in all three sections of the lap but was especially slow on the third, fastest section.

Mercedes is on course for its second disappointing street-circuit race after struggling on the comparatively low-grip, twisty circuit in Monaco. Hamilton was seventh and Bottas failed to finish when a wheel nut seized. Baku challenges the teams to balance straight-line speed with enough grip to handle a narrow, technical section around the old city.

Red Bull's speed could add to a dispute with Mercedes about what Hamilton has previously called “bendy” rear wings on the cars. The wings are believed to flex into a flatter profile at high speed, potentially reducing drag and increasing pace on the long straight at the Baku street circuit.

New tests for the wings have been announced by governing body FIA but only take effect for the next race in France.

Friday was also a triumph for Ferrari, which was the only team with comparable pace to Red Bull.

Carlos Sainz was third, .128 seconds slower than Perez, and Charles Leclerc was fourth after losing his front wing when he locked up a wheel and slid into the barrier.

Ferrari had good pace on another street circuit in Monaco as Leclerc took pole but then couldn't start the race because of car damage. Leclerc had predicted the long straight in Azerbaijan would work against his team though.

Running time in the second session was limited and fragmented because of Leclerc's issues and a red flag when Nicholas Latifi came to a halt in his Williams with engine trouble.

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