 In July 2005, Ryu was selected by the Hanwha Eagles as the 1st pick in the second round of the 2006 KBO League Draft, and made his professional debut on April 12, 2006.In his rookie year of 2006, Ryu finished with an 18–6 win-loss record, a 2.23 ERA and 205 strikeouts in 201.2 innings pitched.He earned the pitching Triple Crown, and was eventually named both Rookie of the Year and Player of the Year.