Born on December 4, 1986, in Houston, Texas, Clemens was a two-sport star at Memorial High School, splitting time between football and baseball, before he suffered a back injury ending his brief football career.[1]
Clemens had a .413 batting average as a junior, with 4 home runs and 23 runs batted in (RBIs) in 2004.[2] He had a .519 batting average and was named all-state in his senior year. As a pitcher, he had a 7–1 record and a 1.75 earned run average (ERA).[3]
In 2006, Clemens played with the Class A Lexington Legends of the South Atlantic League, where he batted .229 with 5 home runs and 39 RBIs in 91 games. His sole appearance as a pitcher in professional baseball was for the Legends in 2006.[5] On June 25, 2006, Clemens was in the news in a game against the Asheville Tourists. He was declared safe in a controversial play on second, leading the Tourists manager Joe Mikulik to go on a rampage.[6]
Through 2006 in the minors, Clemens batted .249 with 9 home runs, 63 RBIs, 7 stolen bases (while being caught once), and a .385 slugging percentage in 449 at bats. That season, he hit a home run off his 43-year-old father, Roger Clemens, in a minor league exhibition game. In Koby's next at bat, Roger threw a brushback pitch at Koby in retaliation.[7] Father and son also played a game together in 2006, when the elder Clemens was making his comeback with the Astros and pitched a game for Lexington.[8]
Clemens started playing at the Puerto Rico Baseball League with the Mayagüez Indians as a first baseman in the fall of 2011. However, he abandoned the team abruptly on November 10, 2011. There were rumors his father persuaded him to leave the island because of the kidnapping of Washington Nationals catcher Wilson Ramos in Venezuela the day before. For abandoning the team with no reason given, Clemens was banned from playing baseball in the Caribbean Baseball Confederation.[10]
On February 9, 2012, Clemens signed a minor-league contract with the Toronto Blue Jays. During the 2012 season, he played for the Blue Jays' Double-A affiliate, the New Hampshire Fisher Cats of the Eastern League, and their Class A-Advanced team, the Dunedin Blue Jays of the Florida State League as a catcher, first baseman, third baseman, outfielder, and designated hitter. He was released at the end of the season.[11]
In February 2015, Clemens was hired as a minor-league spring training instructor for the Astros farm system.[13] He also owns his own company, Koby Clemens Baseball Clinics, offering individual and private lessons.[14]
