Formula One returns to China for the first time in five years this week with a packed programme including a Saturday sprint race, but not everyone is happy with the Shanghai schedule.

Championship leader Max Verstappen and Ferrari's Carlos Sainz are among those who have expressed doubts about having limited practice on a resurfaced circuit that is unknown to the current specification of F1 cars.

China's closed borders during the pandemic meant the Shanghai International Circuit has not hosted a grand prix since April 2019, when the race was won by Lewis Hamilton in a Mercedes one-two with Valtteri Bottas.

This weekend has just 60 minutes of free practice on Friday morning ahead of sprint qualifying, leaving drivers fearful about the lack of preparation.

"I think it's not great," said Red Bull's three-time world champion Verstappen about F1's choice of China as the first of the season's six sprint venues.

"When you have been away from a track for quite a while you never know what you're going to experience," added Verstappen, who has never won in China.

There will be at least one contented face in the paddock -- Sauber's Zhou Guanyu will be driving in front of his own fans for the first time in Formula One.

Shanghai-born Zhou was a five-year-old spectator at the inaugural Chinese Grand Prix in 2004.

"I couldn't be more excited to finally race on home soil in Shanghai," said Zhou, who drove an F2 car for Renault at the circuit in 2019 before stepping up to F1 in 2022.

"To be the first Chinese driver ever to compete in Formula 1 in China means a lot to me. It fills me with immense joy, pride and responsibility.

"I have fulfilled my dream."

The sprint weekend schedule has changed this season, with Shanghai's 19-lap sprint race on Saturday morning followed by main qualifying in its normal afternoon slot to determine the grid for Sunday's 56-lap grand prix.

This generation of F1 cars run much lower to the tarmac than those that raced half a decade ago.

Drivers can be penalised if planks protecting the floor of the car show excessive wear, caused by hitting unexpected track undulations -- something that can also throw cars out of control.

- 'Going to be tough' -

Verstappen has won three out of the four grands prix this season with Sainz taking the chequered flag in the other, in Melbourne.

The Spaniard too has concerns about this weekend.

"I think it's going to be a tough weekend for everyone. With how tricky one bump could make the car, I think it's not a good choice to choose to put the sprint after four or five years' absence," said Sainz.

"Maybe for people watching at home it's exciting, but for engineers and drivers, it's something that, in my opinion, we shouldn't take the risk and have a normal weekend."

Mercedes were previously the dominant force on the 5.451km Shanghai circuit, winning six times from 2012.

But the Silver Arrows have struggled again this season.

Both failed to finish in Melbourne and in the last race, the Japanese GP, George Russell and Hamilton were seventh and ninth respectively.

It was a Red Bull one-two at Suzuka and Mercedes were also well beaten by both Ferraris, with the McLaren of Lando Norris and Aston Martin's Fernando Alonso finishing ahead of Russell as well.

Ferrari's Charles Leclerc and Sainz look the most likely to challenge the dominance of Verstappen and Red Bull teammate Sergio Perez.

Leclerc said Ferrari's race pace was not the issue, it was qualifying they needed to improve.

"We've had some difficulties putting the tyres in the right window on the out laps in qualifying," said the Monegasque.

"So we really have to focus on that to make sure we can put it all together in China."