Kelderman crashed out of the Giro d'Italia in 2017 before Dumoulin went on to take his maiden Grand Tour victory. Kelderman bounced back to secure a fine fourth place finish at the Vuelta a Espana in his first season with Sunweb.
Speaking exclusively to Cyclingnews, Kelderman hinted that Dumoulin could target the Tour de France in 2018, with Kelderman riding as a support rider in July. Both riders, and Team Sunweb, have yet to announce their Grand Tour plans for 2018, insisting that no decisions will be made until all three Grand Tours have presented their routes for next year. So far only the Tour de France has unveiled its parcours, with the Giro d'Italia set to follow suit in late November.
"We've still not talked about the programme but for sure I've talked to Tom. I'd really like to ride with him and I think we're a good combination," Kelderman told Cyclingnews.
"We've a good climbers group and I want to do it [ed. the Giro] again. We'll see if it's the Tour or the Giro but I think for Tom it will be the Tour. Maybe I do the Giro and then the Tour but I don't know yet. We've talked a bit with the coaches but I'd like to do the Giro again for GC."
A new start and back to basics
Kelderman joined Sunweb last winter after spending the first part of his career at the Rabobank – which later formed into Belkin, Blanco and then LottoNL Jumbo. After an impressive start to his pro career Kelderman - still only 26 - went off the boil in 2015 and 2016, and struggled to match results from earlier seasons. According to the rider he needed a change of scene, so when Sunweb approached him with the offer of a three-year contract and a fresh start, he jumped at the chance.
"It's been a great year. This was a new year, and a new start for me," he told Cyclingnews.
"I felt good right from the beginning and had a decent winter before having a top ten at the Tour Down Under. I just went back to basics. I started training and eating well and simply started to live like a cyclist again. The last few years I looked at the details a lot more - things like material, exercise and too much on nutrition, and in a way I became too much of a perfectionist. I just decided to enjoy things a lot more, and enjoy riding my bike.
"In 2014 I had a really good season with top tens at the Giro and the Dauphine but then after that the results were not as good. I was a leader a lot of times and maybe it was a bit too much pressure on myself. I wanted to show that I could do better, and that I could do more results, so I looked at the smaller details but I went too far."
Kelderman took top ten places in every single one of the stage races he completed in 2017. The year certainly wasn't without setbacks or incidents with a crash in Strade Bianche and then another high profile fall involving a parked police motorbike, ending his Giro d'Italia.
That incident robbed him of the chance to support Dumoulin in the second and third weeks of the race but the former LottoNL rider bounced back, picking up a respectable fourth at the Tour de Pologne, before taking the same result in a super competitive Vuelta a Espana.
Once again Kelderman had to deal with a number of hurdles on route to that result. He lost time in the first mountain test after not drinking sufficiently, and then had to deal with Warren Barguil's antics, with the Frenchman eventually sent home after disobeying team orders and failing to wait after the Dutchman punctured.
"I don't really want to talk about it but we had some goals and I was meant to be there for GC and what he did... we didn't really talk about that before the race. I punctured and he didn't wait. There were some things before but it was the team's decision to take him out.
"We're a team. I worked for him at the Classics and I worked for Tom Dumoulin and I get it back later. That's how we work in this team, so if you say 'I'll do it, I'll do it,' and you don't, then it doesn't work."
After losing Barguil to team orders, Kelderman rallied and consistently climbed the overall classfication. By stage 11 he had moved up to fifth and with one mountain stage to go he sat third overall. Although he dropped to fifth on the L'Angliru stage – and eventually rose to fourth after Alberto Contador sat up before finish of stage 21 – Kelderman still recorded his best ever Grand Tour result.
"That was a really amazing result for me. I didn't expect that at all. I knew that I was at a good level but I can put it down to the start of the year.
"I think next year is going to be my seventh or eighth season. I've done almost all the pro races but I hope I've not hit my best yet. This year was a good one for me with the results but it wasn't a stable year because of the injuries. If I can have more stability maybe I can grow and get better."