In the 2008 season, Jong took a role as a utility pitcher for the Lions, pitching 127 innings in 53 games, starting 7, going 10–4 with an ERA of 3.40 and 11 holds in the process.

Although Jong was expected to garner nothing but mopup duties for the team, he was brought up in the five critical games as a long reliever because of the multiple injuries to the South Korea's bullpen.

Jong appeared in the semifinal game against Venezuela, and pitched a 1.1 inning no-hitter, striking out MLB All-Star sluggers Melvin Mora, Carlos Guillén and Magglio Ordóñez.

In the 2009 KBO season, Jong appeared in 62 games, taking a role as a utility pitcher and posting 8 wins, 6 saves and 16 holds.

Due to his good performance in the 2009 World Baseball Classic, many netizens in South Korea called him "Guk-no" which means "national slave".