[5] The Ukrainian turned pro in 2002 by joining the Belgian team Landbouwkrediet–Colnago and delivered some strong showings, most notably in the Giro d'Italia where he finished third in 2003 and fifth in 2004, when he wore the pink jersey during three stages.

In the 2006 Tour de France, Popovych was considered one of the Discovery Channel team's four leaders, along with José Azevedo, Paolo Savoldelli and George Hincapie.

In the Tour de France, he finished eighth while working for Discovery Channel team-mates Contador and Levi Leipheimer.

[9] Popovych was recruited as a domestique member of the Tour de France team primarily to support lead rider Cadel Evans, but had a rather disappointing year, with only a 3rd place in Paris–Nice to show for.

In 2009, Popovych and Armstrong joined the Kazakh-based cycling squad Astana, where many other former Discovery Channel riders and staff were also under contract.

Postal Service cycling team, after Sports Illustrated magazine reported that in November 2010 his property in Tuscany had been searched by Federal Officials who discovered drug testing documents, medical supplies and performance-enhancing drugs as well as evidence of links to controversial Italian physician Michele Ferrari.