Professional career

Cincinnati Reds

Koronka was selected by the Cincinnati Reds in the 12th round of the 1998 MLB Draft. While playing in the Reds farm system with the Stockton Ports in 2002, he was named to the California League All-Star team. On December 16, 2002 he was selected by the Texas Rangers in the Rule 5 Draft but did not make the Rangers opening day roster and was returned to the Reds on March 21, 2003.

Chicago Cubs

Koronka was traded by the Reds to the Chicago Cubs on August 26, 2003 for Phil Norton. He made his major league debut for the Cubs on June 1, 2005 against the Los Angeles Dodgers and gave up 3 runs over 5 innings, walked 3, and struck out 5 for the win.

Texas Rangers

On March 31, 2006, Koronka was traded to the Texas Rangers for Freddie Bynum, whom the Rangers had just acquired from the Oakland Athletics. Koronka started 23 games for the Rangers in 2006, going 7-7 with a 5.69 ERA. He was expected to compete for a spot on the rotation in 2007, but failed to make the Rangers' big league roster. He was optioned to the Triple-A Oklahoma RedHawks prior to the start of the 2007 season.

Koronka made two starts in 2007 for the Rangers going 0-2 with a 7.84 ERA.

Cleveland Indians

He was designated for assignment on July 1, 2007, and subsequently claimed off outright waivers on July 9, 2007, by the Cleveland Indians. He was assigned to their Triple-A team, the Buffalo Bisons. With the Bisons, he made 9 starts and went 3-3 with a 3.54 ERA.

On September 1, 2007, he was designated for assignment and outrighted to the minor leagues on September 12. Koronka opted for minor league free agency on November 3, 2007.

Colorado Rockies/Orix Buffaloes

On December 21, 2007, the Colorado Rockies signed Koronka to a minor league contract with an invitation to spring training. He was 5-3 in 13 appearances (12 starts) for the Colorado Springs Sky Sox. On June 23, 2008, the Rockies released Koronka so he could sign with a Japanese team, the Orix Buffaloes. He started 3 games for the Buffaloes, finishing 0-1 with a 6.75 E.R.A..

Florida Marlins

On January 13, 2009, Koronka signed a minor league deal with the Florida Marlins. He started two games for the Marlins (0-2, 11.75 E.R.A.) and spent most of the season with the New Orleans Zephyrs. He was granted free agency on October 8, 2009.

Los Angeles Dodgers

On January 28, 2010, Koronka signed a minor league contract with the Los Angeles Dodgers with an invite to spring training. He began 2010 with the Chattanooga Lookouts in the Double-A Southern League. After seven starts with the Lookouts he was promoted to the AAA Albuquerque Isotopes. He made one start with the Isotopes, allowing eight runs in 11⁄₃ innings. He was released on June 2.

Lancaster Barnstormers

On July 26, 2010, Koronka signed a contract with the Lancaster Barnstormers of the Independent Atlantic League. He was released on August 3, 2010. He was re-signed on March 8, 2011.

•The Cubs made former big league pitcher John Koronka a regional scout in charge of Florida on Dec 5th,2011. Koronka, 31, last pitched for the Marlins in 2009, which means he is retired.

[ Source: Wikipedia ]