Charles Leclerc will start the Russian Grand Prix from the back of the grid as Ferrari give a debut outing to a new power unit.

The Scuderia have long been teasing a "significant" engine component development, and it will now be put to the ultimate test this weekend.

With regulations restricting Formula One engine manufacturers to one upgrade per component each year, Ferrari have been running a hybrid system based on 2020 specifications.

In Sochi, the team will showcase an improved hybrid power unit and Leclerc will be the first to get to grips with it, as Carlos Sainz waits his turn.

"Its main purpose is to gain experience for the 2022 car project," Ferrari, who will unveil an entirely new car next year, said in a statement.

"A great deal of effort has gone into this, both technically and logistically, and so as to be able to use it as soon as possible, its introduction will be staggered between the drivers.

"Charles will be the first to have the new hybrid system. This decision is a precautionary measure relating to the potential risk of using the battery pack damaged in his Hungarian GP accident.

"In Sochi, Leclerc will have a brand new power unit and will therefore start from the back of the grid.

"As to when the updated hybrid system is fitted to Carlos' car, that will be decided following an evaluation of the right compromise between competitiveness and the impact of the penalty."

Leclerc sits sixth in the driver standings on 104 points, just ahead of his team-mate, who has 97.5 points.

Max Verstappen believes George Russell will make life "very difficult" for Lewis Hamilton if he replaces Valtteri Bottas at Mercedes next year.

Williams driver Russell has been tipped to take Bottas' seat, with Silver Arrows boss Toto Wolff having revealed his desire to finalise his driver line-up for 2022 this month.

Russell stepped in for Hamilton at the Sakhir Grand Prix last year after the seven-time Formula One world champion tested positive for coronavirus.

The 23-year-old also conducted a Pirelli tyre test for Mercedes ahead of the mid-season break and Verstappen thinks his arrival would keep his fellow Brit Hamilton on his toes.

"If he joins then for sure he will make it very difficult for Lewis,” Verstappen, who trails Hamilton by three points in the battle for the title, said ahead of the Dutch Grand Prix this weekend.

"He jumped into the car in Bahrain and basically from lap one he was making it very difficult for Valtteri, so you can only imagine the more experience you gain in that car and the more you get accustomed within the team, naturally you're going to get faster.

"When you do your first race you're guided by the team about setup direction because you just don’t know what to do really, initially, with the car.

"I remember my first race at Red Bull, the thing I said was is that we will just follow a bit what Daniel [Ricciardo] is doing because I have no clue about what this car needs to go quick because even though F1 cars look pretty similar, the way of setting them up can be very different.

"I am very confident - already what you could see with the performance he did in Spa was really good.

"Of course, they set up the car a bit more for wet conditions but nevertheless to do that in a Williams was very impressive. I do expect him to do very well if he gets that seat."

Ferrari driver Charles Leclerc echoed Verstappen's sentiments.

“I have actually been team-mates with George for a year in karting and I think what I have seen of him since that time, is just that he is extremely talented," he said.

"Every time he gets into the car he's just quick straightaway, so his talent makes him special.

"If he goes to Mercedes next year, and I hope he does because I think he deserves a chance there, I'm pretty sure he will perform very, very well and impress more than one person."

Remarkable late drama at the Azerbaijan Grand Prix saw Sergio Perez handed victory after Max Verstappen crashed out and title rival Lewis Hamilton incredibly finished outside the points.

Verstappen looked to be coasting to a second consecutive Formula One win and seventh straight podium – both career firsts.

The Red Bull driver, four points ahead of Hamilton in the standings prior to the race, was well in the clear after earlier benefitting from a slow Hamilton pit stop.

But Verstappen's left-rear tyre blew out and ended his race, prompting the furious Dutchman to kick his car in anger.

Lance Stroll had encountered the same issue with the hard Pirelli tyres, swerving out of control when he had been fourth, albeit without pitting.

A red flag – requested by a concerned Red Bull team – followed Verstappen's crash with just three laps remaining, meaning a standing start with Perez ahead of Hamilton on the front row of the grid following the delay.

In another twist, Hamilton and his smoking brakes careered off the circuit from the restart and Perez raced away to lift Red Bull spirits.

With Hamilton way back in 15th, it meant a positive end to the day for Verstappen's team, even if the season leader will continue to rue his misfortune.

Both Verstappen and Perez jumped ahead of Hamilton when he was delayed in the pit lane by Pierre Gasly, having quickly caught pole-sitter Charles Leclerc.

Stroll's mishap threw a spanner in the works, yet Verstappen pulled ahead clear from the restart following the safety car, with Perez again getting the better of Hamilton.

Sebastian Vettel's climb to fourth and attempt to reel in old foe Hamilton looked the most likely source of intrigue in the closing stages, only for Verstappen's blow to bring the race to a standstill.

Hamilton admitted his error when his restart sensationally failed, though, and Perez hung on, his car breaking down moments after crossing the line before Vettel – who achieved a first Aston Martin podium.

Charles Leclerc found it "very difficult to feel okay" after his latest failed attempt to finish a Monaco Grand Prix, in which he was unable even to take his place on the grid.

Leclerc had qualified fastest on Saturday but crashed in the process, giving the Ferrari mechanics work to do to get his car in shape to start from pole position.

The Scuderia announced three hours before the race they would not have to replace the gearbox, ensuring Leclerc would not face a grid penalty.

However, the 23-year-old quickly ran into trouble driving the car ahead of the start, as Ferrari identified "an issue with the left driveshaft" that meant he had to be withdrawn around 20 minutes prior to the grand prix.

The Monegasque was making his third Formula One appearance at Monaco having retired from the prior two.

But for this mishap, Leclerc might have produced the best result of a home driver in the principality, a feat that still belongs Louis Chiron, who came third at the first ever F1 Monaco GP in 1950.

"In the garage, it was very, very difficult to feel okay," Leclerc told Sky Sports.

"I guess now I'm getting used to this feeling here, unfortunately. I've never finished a race here. This year I don't start it starting from pole.

"It's a difficult one to take, but I also feel for the team, to be honest. The mechanics have done such a hard job yesterday to try to check everything.

"The mechanics were finally a bit happy this morning to see that everything seems fine and all the parts were fine, and then this happens. It's a shame for everyone."

Max Verstappen, who started from second but had a clear run with Leclerc's position vacant, won at Monaco for the first time, finishing ahead of Carlos Sainz in the second Ferrari car.

Sainz delivered Ferrari's 54th Monaco podium, extending their record haul.

Max Verstappen roared to victory at the Monaco Grand Prix and jumped above reigning Formula One champion Lewis Hamilton at the top of the drivers' standings.

The Red Bull driver benefited from the shock withdrawal of pole-sitter Charles Leclerc ahead of the race, producing an immaculate drive to stay out of trouble and finish ahead of the Ferrari of Carlos Sainz.

McLaren's Lando Norris completed the podium, securing his second third place of the season, with Sergio Perez, Sebastian Vettel and Pierre Gasly all coming home ahead of Hamilton, who trailed in a distant seventh.

The outcome saw Verstappen, thanks to his first Monaco triumph, move four points in front of Hamilton after five rounds of the 23-race championship. He leads the championship for the first time in his career, a further sign that Hamilton could face a major battle to cling to his crown as he chases a record-breaking eighth title.

Just 20 minutes before the race began, Ferrari dropped the bombshell that Leclerc had been ruled out due to a driveshaft problem.

It was a crushing blow for the Monegasque driver, whose pole was secured in dramatic fashion on Saturday when he crashed his Ferrari in the final minute of qualifying, denying his rivals a clear track and the chance to set a faster time. Leclerc feared gearbox trouble but was initially given the all-clear to race, until he was pulled from the line-up.

What it meant was that Verstappen, second on the grid, had the chance to gain the early ascendancy on the tight circuit where he had never previously achieved a podium finish, and he demonstrated his prowess as a front-runner.

Valtteri Bottas was sitting second when the Finn pitted on the 31st lap, and he joined Leclerc in the bad-luck club when Mercedes were unable to remove his front-right wheel. After a desperate minute of waiting, Bottas climbed out of his car, his race over.

Sebastian Vettel managed to get ahead of Pierre Gasly and Hamilton when the three pitted, the Aston Martin going almost wheel to wheel with Gasly's Alpha Tauri as he completed a stunning overcut.

That moment imperilled Hamilton's leadership of the championship, putting him down in seventh place, as Mercedes suffered a miserable couple of minutes. 

It proved the last major twist of the race, with Hamilton securing a bonus point for a late fastest lap. Small consolation on a dismal day for Mercedes, as Verstappen and Perez's performance also saw Red Bull go ahead of the Silver Arrows in the constructors' standings.

Charles Leclerc's hopes of finally succeeding at his home grand prix were ended for another year in late, frustrating fashion at Monaco on Sunday.

Leclerc set the fastest time in qualifying but then crashed, cutting short the session to secure pole position yet leaving his Ferrari damaged.

The Scuderia tested Leclerc's gearbox on Saturday and again on Sunday, attempting to avoid a change that would mean giving up their place on the front row with a grid penalty.

The Monegasque star was cleared to take his position on pole less than three hours before the race, but Ferrari's determination not to replace the gearbox seemed to have proved costly.

A driveshaft issue was revealed when running the car, which meant Leclerc was unable to start the race, leaving his precious pole position vacant.

The problem was "impossible to fix in time for the start of the race", Ferrari said just 18 minutes before the scheduled start.

Max Verstappen had a clear run from second on the grid, as Leclerc rued another painful weekend at his home event.

His previous two Monaco appearances saw him fail to finish, although he completed enough of the 2018 grand prix to come 18th. At no other circuit has Leclerc had to retire twice.

The 23-year-old was denied the opportunity to surpass Louis Chiron's result as the best from a Monegasque driver at their home race. 

Chiron came third for Maserati in 1950, the first ever Formula One Monaco Grand Prix.

Charles Leclerc has been putting in the hours to ensure Ferrari bounce back from their worst season for 40 years.

In 2020, Leclerc finished eighth in the drivers' standings, with 98 points and two podiums to his name.

Even that fairly meagre return meant he fared better than Sebastian Vettel, who had 33 points and a solitary podium down in 13th.

The former world champion has joined Aston Martin for 2021 following the lowest points total of his career, with Carlos Sainz in place as Leclerc's new team-mate.

The Monegasque was cautiously optimistic at Friday's season launch, having left few stones unturned during the off-season, but he knows it is foolish to predict how a wounded Ferrari might fare against Formula One's other heavyweights.

"There has been a lot of work. We have been pushing quite a lot," he said.

"It always looks positive on paper but then we need to see what the others have done as a step.

"I have never been in [the] Ferrari [factory as much] as before this season. We have been doing quite a bit of tests with the old car. I feel very ready.

"I have been working in a similar way as in the past, trying to understand what my weaknesses were last year.

"I still believe tyre management is something I should push. I improved a lot last year and I hope there will be another step this year."

Last month, Leclerc was forced to put such intensive preparations on hold as he self-isolated having tested positive for coronavirus.

However, he offered assurances that there have been no lingering effects.

"COVID did not hit me that bad," said the 23-year-old. "I did some physical tests to make sure everything came back to normal and that is the case."

Having comprehensively out-driven Vettel as the younger man, Leclerc anticipates a different dynamic when Sainz – fresh from two seasons at McLaren – joins him on the grid for the 2021 opener in Bahrain on March 28.

"It is very clear we need to push for the team," he added.

"Carlos wants to beat me and I want to beat him too. We will try to be careful when we fight each other on track.

"What is most important is we separate what happens on the track and off the track. It is a fine line that every team-mate needs to find.

"Carlos is very competitive but he is also here for the benefit of the team, as I am. We will have to play it smart on that one."