Upon graduation from the school in 2000, he was selected by the LG Twins with the 11th pick in the 2nd round of the 2000 KBO Draft, but chose to play college baseball at Hanyang University instead of turning pro.

In November 2003, as a senior Shim was named as a member of the South Korean national team for the 2003 Asian Baseball Championship in Sapporo, Japan.

In 2008, Shim spent most of the season in the reserve team, failing to earn his spot either in the starting rotation or in the bullpen due to the decrease of ball velocity and the absence of command.

On August 3, Shim lost a record 18th straight game, allowing 3 earned runs in six innings pitched against the Samsung Lions.

On August 9, Shim finally won to break a streak of 18 consecutive games lost, hurling 6.1 innings of one-run ball in a 3–1 victory over the Lotte Giants.