Viciedo struggled in his first season in the national series, hitting only .243 through the season's first 50 games. However, in his second season, at age sixteen, he hit .337 with 14 home runs. Viciedo was selected to Cuba's provisional 60-player roster for the 2006 World Baseball Classic, but was not included in the final team.
On May 20, 2008 Viciedo defected from Cuba with his family on a boat bound for Mexico. Once in Mexico he crossed the border to the United States and went to Miami where he was reunited with some of his family. He is expected to sign with a Major League Baseball team shortly as an international free agent and receive a signing bonus of more than a million dollars.