More than any other race, Paris-Roubaix is a race where someone can surprise the field and take an unexpected win. The old adage goes that one has to keep riding, because you never know what happens over the seemingly endless cobbled sectors.
Just ask Mat Hayman, who shocked by winning in front of Tom Boonen in 2016, or Florian Vermeersch, who unexpectedly finished second in the muddy Roubaix of 2021.
Truth be told, none of the riders in this list are quite as surprising as that pair, and would not be thought of actual outsiders should they triumph in the velodrome, but it certainly would be unexpected, especially given the strength in depth of both the men's and women's peloton.
It's harder to nail down what would be a surprise in Paris-Roubaix Femmes, due to the nascent nature of the race; as it is in just its third edition, no one can be quite sure how the race is supposed to go.
The men's race is just as chaotic, but there is 120 years of history to look back on and pore over in guessing who is going to win. However, as I said, none of the four male 'wildcard' picks are totally out of left-field, given all four have finished on the podium of monuments in the past.
Read our lists of the favourites for the men's Paris-Roubaix, and favourites for Paris-Roubaix Femmes, as well as our how to watch Paris-Roubaix guide, and our page on the route and start lists.
Filippo Ganna (Ineos Grenadiers)
Paris-Roubaix sort of has Filippo Ganna's name written all over it. The flat, power race is the perfect setting for the Hour Record holder to show his watt-producing prowess, but it has not quite happened yet.
The Italian won the under-23 version of the race, as did Tom Pidcock, but this is not the best predictor of future success at Roubaix, as the list of its winners shows.
However, one can picture the Ineos Grenadiers rider powering off on the flat, just as his former teammate Dylan van Baarle did last year. He was 35th on that occasion.
"Paris-Roubaix is like playing Russian Roulette" Ganna said this week. "Each time, you pull the trigger and you hope that the bullet doesn't come out."
Lorena Wiebes (SD Worx)
Can you be a wildcard if your team wins every cobbled Classic and you are one of the best riders in the world? It's an interesting question.
Lorena Wiebes is not quite enough of a cobbled specialist to be among the absolute favourites for Roubaix, but if she is there at the end of the race in the velodrome, few would bet against her in a sprint finish.
The Dutch SD Worx rider has won three races this season, including Scheldeprijs on Wednesday, and made the elite selection at the Tour of Flanders last weekend, so is clearly on good form.
With Lotte Kopecky her team's undisputed leader, one could see the flying Dutchwoman sneaking into a chasing group and then triumphing at the end of the 145km race.
Matej Mohorič (Bahrain-Victorious)
Another rider who is not so much 'outside the box' as much as just not one of the top favourites, Matej Mohorič finished fifth at Paris-Roubaix last year, but for a time looked like he could be on to win, and might just do that again.
The Slovenian has had a good Classics season, finishing third at Kuurne-Bruxelles-Kuurne, sixth at Strade Bianche, and eighth at Milan-San Remo, which he won last year, and seventh at the E3 Saxo Classic. He might have abandoned the Tour of Flanders last week, but will be motivated for something special on the cobbles of northern France.
His Bahrain-Victorious team, with Fred Wright, Andrea Pasqualon and Jonathan Milan, is relatively strong, and Mohorič could be the next rider to solo to victory.
Lucinda Brand (Trek-Segafredo)
Lucinda Brand finished third at Paris-Roubaix last year, so again, is not exactly a ridiculous choice for who will win over the cobbles. If her Trek-Segafredo team are to keep up its record of winning every single Roubaix with a different rider, then one would imagine it would either be Brand or Elisa Balsamo to succeed Lizzie Deignan and Elisa Longo Borghini.
The cyclo-cross star has the bike handling skills to help her at Roubaix, and her 12th place at the Tour of Flanders shows that she is in good form. However, her challenge is to surmount the overwhelming strength in depth that SD Worx will present, which might prove too difficult.
Sep Vanmarcke (Israel-Premier Tech)
It would be a shock if Sep Vanmarcke won Paris-Roubaix. Not because he doesn't have the skills to triumph over pavé, but because he has so often been the nearly man, and never the champion.
The Belgian, now at Israel Premier-Tech, has finished fourth at Roubaix three times, sixth once, and ten years ago, he finished second behind Fabian Cancellara in the velodrome.
At 34, Vanmarcke is not over the hill yet; his third place at Gent-Wevelgem proved that he still has a result in him, but he would need to overcome his runner-up status to win. It might be too much.
He was supposed to be the coming thing in Belgian cycling for so long, now, on the way down from his peak, perhaps there is one more big ride in him. Perhaps.
Audrey Cordon-Ragot (?)
The main reason Audrey Cordon-Ragot is a wildcard is because at time of writing the Frenchwoman's new team has not been announced. There have been rumours linking her to Human Powered Health - a team with a convenient spot free on the startlist - something the UCI's website appears to confirm, but the news is yet to be released by the American squad.
She left Zaaf due to riders being left unpaid, and was previously involved in the collapse of the B&B Hotels project, so Cordon-Ragot has a lot to make up for. If she won, expect an angry celebration.
It's not impossible to imagine either, with the 33-year-old finishing eighth in the first edition of the race, and taking top fives this year in both the Omloop van het Hageland and Le Samyn des Dames in February.
Florian Vermeersch (Lotto Dstny)
Feels reasonably ridiculous putting a man in as a wildcard who finished second at Paris-Roubaix as recently as 2021, but Florian Vermeersch is certainly not a top-tier favourite, and it would be a surprise if he triumphed.
However, the 24-year-old has had a solid, if not spectacular, Classics season, the highlight of which was being in the decisive move at the Tour of Flanders last weekend, eventually finishing 12th.
Vermeersch now has the experience of two Roubaixs behind him to take into this year's edition, and if he finds himself up the road again, do not count against him.
Arlenis Sierra (Movistar)
Fifth at Danilith Nokere Koerse, fourth at the Trofeo Alfredo Binda, and tenth at the Tour of Flanders, Arlenis Sierra is improving in Classics racing, and has a sprint that does not seem to be heavily impacted by great distance.
The Cuban Movistar rider won the bunch sprint for fourth place at Flanders last year, and should she make the velodrome in a small group, would bet on her speed to take her to victory.
It's her speed which might make other teams loathe to bring back one of her teammates should they go up the road, in the knowledge that Sierra was in the bunch, so Movistar could use this tactic to make hay.
