Cyclingnews understands Sagan has travelled to Tuscany and intends to start the week-long stage race but the condition of the three-time world champion has been seriously affected by a stomach virus. He has suffered with diarrhoea and has struggled to eat normally for the last five days.
Sagan will not attend the pre-race Tirreno-Adriatico press conference on Tuesday afternoon or study the team time trial course. Instead he and some Bora-Hansgrohe teammates will do a short ride from the hotel the team used for the GP Industria & Artigianato race in Montecatini Terme, near Florence to Lido di Camaiore.
Fortunately, Tirreno-Adriatico begins with a 21.5km team time trial around Lido di Camaiore on Wednesday, giving Sagan an extra day to recover before the hilly road stages on Thursday. Sagan will be joined by Maciej Bodnar, Marcus Burghardt, David Formolo, Oscar Gatto, Rafal Majka sand Daniel Oss in the Bora-Hansgrohe line-up for Tirreno-Adriatico.
Sagan made his season debut at the Tour Down Under in Australia and went on to ride the Vuelta a San Juan in Argentina. He won a stage at the Tour Down Under and finished second and third in sprints in Argentina but considered both races as early-season preparation for the spring Classics.
He plans to target all the Classics from Milan-San Remo to Liege-Bastogne-Liege and so opted to miss Strade Bianche and delay his return to racing until Tirreno-Adriatico so that he could complete a later and longer block of training at altitude at Sierra Nevada in Spain.
He has reportedly trained well at altitude but his form has now been affected by the stomach virus. It will be vital for him to recover and ride Tirreno-Adriatico so that he can be back on form for Milan-San Remo on Saturday March 23.