The 2017 Giro d’Italia was meant to be a landmark moment for Geraint Thomas, leading his team in a Grand Tour for the first time and embarking on what he called “uncharted territory”.

Then it all fell apart.

Wilco Kelderman collided with a police motorbike stopped at the side of the road, swerved to his right and caused a crash which sent Thomas and others in the peloton tumbling.

Injured, bloodied but, more than anything, furious, the Welshman soldiered on to complete the next stage before pulling out of the race to recover in time for that summer’s Tour de France.

Thomas was so frustrated that he could not bring himself to watch the rest of the Giro back home in Cardiff, solemnly adding that he had “unfinished business” with the race.

On Saturday, he begins his quest to right that wrong.

Thomas is back in Italy to compete in the Giro for the first time since 2017, and he returns a different rider – a Tour de France champion in 2018 and now leading Ineos Grenadiers on his own, having shared that responsibility with Mikel Landa three years ago.

“It’s always been in the back of my mind, wanting to come back here and have another crack at it,” Thomas tells BBC Sport Wales.

“It felt like I was in great shape then and obviously a crash put an end to that.

“So I’ve always wanted to come back and try and give it a good go – at least finish the race for a start!

“I know I can perform and this year seems to be the perfect opportunity to do that. I think I’m coming into form at just the right time and the motivation for sure is there from the past as well.”

Thomas has been absent from the Giro for the past three years because he has been concentrating on the Tour, winning it for the first time in 2018 and finishing second behind Ineos team-mate Egan Bernal last year.

This year, however, his priorities have changed in a season turned upside down by the coronavirus pandemic.

The Giro usually takes place in the spring with the Tour following in July, before the third of road racing’s holy trinity, the Vuelta a Espana, brings the Grand Tour season to a close in September.

But as a result of coronavirus-enforced postponements, the Tour finished on 20 September, the Giro begins on Saturday and the Vuelta will not end until 8 November.

Bernal was chosen to lead Ineos in France but, after his title defence went up in flames following a disastrous stage 15, Sir David Brailsford’s team will be throwing their support behind Thomas’s bid to win his second Grand Tour.

“Geraint’s one of the most experienced riders in our team and has been for years, he’s very successful and he’s come a long way since the start of his career with us,” says Brailsford.

“People saw it as a non-selection [for the Tour] but it’s not a non-selection. We’ve known each other a very long time so we could sit down and have a mature conversation about the Tour or look a bit further at the Giro, where he could be competitive in the general classification.

“I think it’s more exciting and a better option for a rider of Geraint’s standing to be here at the Giro, competing for the overall win. I’m very pleased about the decision we made.

“It’s not impacted on our relationship in anyway whatsoever.”

Thomas nods, adding: “I totally agree. We had a really good, long, honest chat and a decision was made and we’re going all guns blazing for the Giro.

“This is what I wanted to do. The only downside was that I’m missing my son Macs’ first birthday, my fifth wedding anniversary and my wife Sara’s 30th birthday.

“But other than that, from a purely professional point of view, I’m super hungry for it and I think it was a good decision. You’ve just got to have the balls to do it.

“Where I am in my career, I want to go to races to perform and win or at least be in the mix. With the Tour I wasn’t quite where I wanted to be so, with the Giro, I feel like I’m in good shape.”

Thomas’ preparations for the race have gone well, with two encouraging performances in Italy in September.

The 34-year-old finished second at the Tirreno-Adriatico stage race and then came fourth in the Road World Championships time trial.

The latter result bodes particularly well as this year’s Giro route features three time trials, including the opening and closing stages, which should suit Thomas.

As ever in a Grand Tour, there are several mountainous stages and the climbs will be especially testing when the three-week race visits the Alps before finishing in Milan.

And as the Giro has been moved from its usual slot in May to October, the weather could have a major bearing on events. Several of the stages’ summit finishes have already been covered in snow, which could lead to stages being re-routed or cancelled.

Thomas has first-hand experience of the weather impacting Grand Tours, having been in contention for the Tour de France yellow jersey when hailstorm brought stage 19 to an abrupt halt last year.

On top of the potentially tricky conditions, Thomas faces strong competition in Italy, with fellow Briton and the man who pipped him to the Tirreno-Adriatico title, Simon Yates of Mitchelton-Scott, among the leading contenders.

Others expected to challenge for the pink jersey – the ‘maglia rosa’ in Italian – include Steven Kruijswijk of Jumbo-Visma, Astana’s Jakob Fuglsang and two-time winner Vincenzo Nibali of Trek-Segafredo.

After last month’s thrilling conclusion to the Tour de France, this year’s Giro has the ingredients for another absorbing spectacle.

And for Thomas, after the injustice of 2017, he will hope to finally see to that unfinished business.

“It would be massive to win. It’s the second biggest race in the world – the history, the fans, it’s a huge race in its own right,” he says.

“I’m one of the favourites but it’s a strong field here. It’s nice to hear people think I’m one of the favourites – I’m just hoping they’re all right.

“I won the Tour in 2018, I was runner-up last year, training has been going well, I was second at the Tirreno-Adriatico, the Worlds time trial went well, so I feel I’m in decent enough shape to be competitive.

“I’m not saying I’m going to come and win the race but I will definitely be there or thereabouts. I’ve done all the hard work and that’s all I can control.

“I’m hopeful that I’ll be in the mix. I’m really looking forward to it now.”