Chris Froome‘s absence is being felt by even his biggest rivals in the Tirreno-Adriatico stage race this week.

The start-list was looking like a who’s who of top road racing talent before the event, but Froome was forced to drop out with a chest infection, while Marcel Kittel also withdrew through illness.

“We were looking forward to [a re-match after Ruta del Sol], but that’s how it is,” said Bjarne Riis, Alberto Contador’s team manager at Tinkoff-Saxo.

“Contador’s most feared rival is Froome, no doubt about that. He knows how good Froome is. We still don’t know how good Nairo Quintana can be, or how well Vincenzo Nibali will go with these guys when they are at their best, but we know how good Froome is, and how good he can be.”

The 2013 Tour de France winner pulled out of Tirreno-Adriatico on Monday, 48 hours before the race was due to start, because of a chest infection. His last-minute move upset the organiser who had hoped to have in attendance all four big Grand Tour stars: Froome, Contador, Vincenzo Nibali (Astana) and Nairo Quintana (Movistar).

“It’s good for the sport to have them together in more than one or two races. One or two is not enough — that’s not what we want to see, and it’s not what the public wants to see,” Riis added. “It’s a shame because you can look at tennis and see how often the big guys meet. That’s what the people want to see, and it’s what we want to see.”

Froome beat Contador in the first head-to-head of 2015 at the Ruta del Sol stage race. Contador won the first big mountain stage, but Froome re-bounded to win the second and take overall victory.

“Ha!” Contador responded when asked if Froome is already one up on him. “You can look at it as Froome 1 and Contador 0, or you can see it as Contador 2 and Froome 1 given I beat him in the first time trial and the first mountain top finish in Ruta del Sol.”

Nibali won the Tour de France last year after both Froome (stage five) and Contador (stage 10) abandoned the race. He has not gone head-to-head in a stage race with Froome since the first days of the 2014 Tour.

Nibali said: “Froome, Alberto… What’s important is for me to race. Clearly though, Froome is a great adversary and rival. I’m sorry that he’s not here, but for sure, there are other occasions to race against him.

“It’s important to face my rivals early on, but the big thing is to be in the best condition at the key moments of the season when you have to face them.”

If their schedules go as planned, Froome will not face Nibali in a stage race until the Critérium du Dauphiné in June. He will not see Quintana – winner of the 2014 Giro d’Italia and second to Froome in the 2013 Tour – until the Tour this July 4.

Froome and Contador should go head-to-head in Spain’s Volta a Catalunya from March 23 to 29. Riis, however, said that it is not a “high-level race” and will not provide the same level of competition between the two that Tirreno-Adriatico would have offered.

Sky’s British leader trained at altitude in South Africa before starting his season at a cold and wet Ruta del Sol. Riis said that he felt sorry for Froome and understood that if he is sick, he cannot race in Tirreno-Adriatico.

He added, “I heard from those in Ruta del Sol that he looks skinny, and if you’re skinny like that in the early season then you get sick.”