Marc Jason Kroon (born April 2, 1973) is an American former right-handed relief pitcher. He served as the closer for the Yomiuri Giants of Japan's Central League.

He was drafted 72nd overall by the New York Mets in 1991. After playing for various teams including the Cincinnati Reds, he joined the Yokohama BayStars in 2005. That year, he set the record for the fastest pitch ever in Japanese baseball, at 161 km/h (100 mph). He threw fastballs at that speed several times while playing in Yokohama. After the 2007 season, Kroon and the BayStars failed to come to terms on a new contract, and ended up being a free agent. Kroon was later signed by the Yomiuri Giants along with two other major non-Japanese free agents: former Tokyo Yakult Swallows standouts Seth Greisinger, and Alex Ramirez.

In 2008, Kroon led the Central League in saves with 41. He also broke his own record of pitching to 162 km/h (101 mph).

Kroon signed a minor league contract with an invitation for spring training with the San Francisco Giants in 2011. Kroon was reassigned to triple-A Fresno Grizzlies at the end of spring training.

Kroon was featured in the Showtime television production The Franchise.

On March 8, 2012, Kroon retired.

[ Source: Wikipedia ]