Vasil Kiryienka, who helped power Chris Froome to his Giro d'Italia and Tour de France titles, is stopping racing due to heart problems.
The 37-year-old has not raced yet in 2019 and decided not to until he is 100 per cent. His last race was the 2018 World Championships, where in 2015 he won the time trial world title.
"All of our riders have a cardiac screening every year – and in Kiry's screening we found an anomaly that required further investigation," Team Sky doctor, Iñigo Sarriegui said.
"Following tests, Kiry is currently undergoing treatment and he will remain sidelined until further notice."
The Belarusian was part of the team that helped Froome to victory in the Giro d'Italia in 2018. He did so as well for the 2016 and 2017 editions of the Tour de France.
Racing in the 2015 Giro d'Italia, originally to help Richie Porte, Kiryienka won the time trial stage in the Prosecco zone to Valdobbiadene.
"The doctors have told us to take caution for a period before Kiry resumes racing," coach Xabier Artetxe said.
"He is still in this period now, so the doctors are looking after him and are monitoring his progress. We need to ensure Kiry is back to 100 per cent before he returns to racing."
The anomaly is taken seriously. Michael Rogers, a former Sky rider, retired due to an arrhythmia. Former Paris-Roubaix winner Johan Vansummeren retired due to an anomaly and a cardiac arrhythmia forced Gianni Meersman to stop riding.
Olivier Kaisen and Wil Walker both ended their careers due to heart problems.
At a more serious level, 22-year-old Daan Myngheer died due to a heart attack in the 2016 Critérium International.
Kiryienka won his first of three Giro d'Italia stages in 2008. To win the stage at the Sestrière ski resort, he attacked on the gravel roads of the Colle delle Finestre like Froome did in 2018.
He grew up in Rechytsa, over the boarder and just 130km from Ukraine's Chernobyl nuclear reactor. Rechytsa links with Chernobyl via rivers. His dad died of radioactive-related illness and his mum of liver cancer.
"But people die of this all the time," he said in 2008 of his mum. "I go in for check ups all the time, but nothing has ever shown."
Kiryienka and Team Sky joined forces in 2013. They have yet to provide further information on the cardiac anomaly.
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