"This morning Vincenzo Nibali fell while he was training near Ponte Tresa, in the district of Lugano, hitting his right hand," Trek-Segafredo said in a statement.
"Clinical examinations at a Lugano-based clinic (X-ray and CT scan) have unfortunately revealed a compound fracture of the radius of the right wrist.
"The Trek-Segafredo medical staff, in agreement with the Team management and Vincenzo, have decided to opt for an immediate osteosynthesis surgery to reduce the fracture, which is scheduled for tomorrow in Switzerland.
"Only after the surgery is performed will it be possible to hypothesize a recovery path and make the necessary evaluations regarding Nibali's participation in the Giro d'Italia."
Nibali, one of seven riders who have won all three grand tours (France, Spain, Italy), prevailed in the Giro in 2013 and 2016.
