If the defending Tour de France champion Jonas Vingegaard overcomes both the lingering aftermath of a horror crash in April that hospitalised him for 12 days, and the rampant form of a seemingly invincible Tadej Pogacar, his will be one of the most remarkable wins in the race’s history.

The double Tour winner starts this year’s race, which begins in Florence on Saturday and ends in Nice on 21 July, in extremis, his embattled team beset by illness and injury, his form uncertain.

Battered, bruised and in some places broken, the Dane has not raced since a high speed crash on a descent in the Tour of the Basque Country left him with fractured ribs, a broken collarbone and a punctured lung.

While Vingegaard has been in rehab, Pogacar has taken over the sport and been given the ultimate, if cliched, accolade of being labelled the “new Eddy Merckx”, hoovering up serial race wins, almost without breaking sweat.

Vingegaard has been involved in his own race against time, holed up in the Alpine ski resort of Tignes, battling to get fit in time for a Tour that begins a week early because of the start of the Paris Olympics. Without him, his Visma-Lease a Bike team have struggled on and been beset by bad luck.

Crashes and Covid have crippled their Tour preparations, with 2023 Vuelta a España winner Sepp Kuss, Vingegaard’s unflagging mountain wingman, the latest to withdraw from the starting lineup. In a Tour with a frightening amount of climbing in the final week, this is another devastating blow.

In stark contrast, Pogacar can do no wrong. He has dominated almost every race he has started in 2024, from Strade Bianche to the Giro d’Italia, via the Volta a Catalunya and Liège-Bastogne-Liège. His one flop came in the Italian Classic, Milan-San Remo, where he could finish only third.

He starts the Tour backed by a support team so strong that the prospect of all three places on the final podium being filled by UAE Team Emirates riders – such as Adam Yates and João Almeida, first and second in this month’s Tour of Switzerland – is not that fanciful.

This time though, Pogacar faces the strongest possible opposition. Lining up alongside Vingegaard, is fellow Slovenian Primoz Roglic, past winner of the Giro and the Vuelta, but yet to claim a Tour de France.

Roglic, now leading the Red Bull Bora-Hansgrohe team, also has a score to settle with his compatriot. Pogacar robbed Roglic of his yellow jersey on the penultimate stage of the 2020 Tour, demolishing his overall lead in a mountain time trial at La Planche des Belles Filles.

Making his Tour debut is the world time-trial champion, Remco Evenepoel, of Soudal Quick-step, another victim of April’s crash in the Basque Country and winner of the Vuelta in 2022, but as yet untested in the claustrophobia of the Tour bubble.

Evenepoel, a former captain of Belgium’s under-16s football team who might have been playing in the Euros if he hadn’t turned to cycling, is a genuine contender for the podium, but fragile team support and an occasionally hot-headed temperament may work against him.

In the face of Pogacar’s dominance, all their hopes are slim. Already there is speculation that the 25-year-old, in devastating form at the Giro in May, might “kill” the race in the opening weekend’s stages to Rimini and Bologna through the hilly heart of Italy.

“The Tour will be over in three or four days,” Groupama FDJ team manager Marc Madiot said. “Pogacar will break things apart and blow out Vingegaard. In his place, that’s what I’d do, to be sure Vingegaard doesn’t get back on top form.”

But if Pogacar fails to do that, the grand finale to this Tour in the climbs of the southern Alps, prior to the last day’s time trial from Monaco to Nice, offers some hope for his rivals to cling to.

The Slovenian has wilted in the Alps in the past and, on both occasions, Vingegaard has seized the moment. In 2022, an over-confident Pogacar collapsed on the Col du Granon and the Dane climbed to a definitive lead in the overall standings.

Last July, Pogacar was found out again, this time on the Col de la Loze. “I’m dead, I’m gone,” he muttered into his radio as he dropped back on the relentless climb, while ahead Vingegaard skipped clear. Asked how he felt at the finish of the stage, Pogacar was direct. “I’m fucked,” he said.

A similarly weary mood is already detectable at Ineos Grenadiers where a multi-leader strategy, allied to the surprise decision to leave the director of racing, Steve Cummings, at home “supporting remotely” has bemused the race convoy.

Cummings was mysteriously absent as the team unveiled a two-rider leadership strategy, fronted by 2019 Tour winner Egan Bernal and Carlos Rodríguez, fifth overall last year, with Geraint Thomas and Tom Pidcock seemingly in supporting roles.

“We sat down on the bus, briefly,” Thomas said, “just to hear each other, what we wanted to get from the race. As long as we’re all pulling in the same direction, which I’m confident we will be. Of course, there will be bumps in the road.”

The British team’s multi-leader strategy has been tested before, most notably in 2021, when Thomas, Richard Carapaz, Tao Geoghegan Hart and Richie Porte, attempted to take on Pogacar. “He can’t follow all of us,” Porte said before that year’s race began. The Slovenian went on to win the Tour by more than five minutes.

• This article was amended on 28 June 2024. An earlier version said that the penultimate stage of the 2020 Tour de France was Plateau de Beille when it was La Planche des Belles Filles.