The Jumbo-Visma rider has not raced since last year's Critérium du Dauphiné because of a knee injury sustained in a crash during the 2019 Giro d'Italia. He was due to race the Volta a la Comunitat Valenciana but fell ill two days before the race and returned home.
Dumoulin explained, "I would’ve flown to altitude camp this Thursday to prepare the next races, but we have to postpone until I feel 100% again. We will change my racing schedule by skipping Tirreno and MSR [Milan-San Remo -ed] to allow me the time I need to get back on full strength again."
Jumbo-Visma said in December that Dumoulin had fully recovered from his knee injury and would have no limitations for his 2020 season.
He was named to the squad's team for the Tour de France and expects to also target the Tokyo Olympic Games.
"It’s such a shame because I was feeling amazing and I couldn’t wait for the season to start," Dumoulin said of missing the March races. "Too bad I need to wait a little longer now. To quote the famous philosopher RUN DMC: 'It's like that, and that's the way it is'."