Shaun Marcum is a former professional baseball player who played as a pitcher in Major League Baseball (MLB) for several teams. He was born on December 14, 1981, in Kansas City, Missouri, and attended Missouri State University, where he played college baseball.

Marcum was drafted by the Toronto Blue Jays in the third round of the 2003 MLB draft. He made his MLB debut with the Blue Jays in 2005 and played for the team until 2010. During his time with the Blue Jays, Marcum established himself as a reliable starting pitcher, with a career record of 37-25 and an earned run average (ERA) of 3.85.

In 2010, Marcum was traded to the Milwaukee Brewers, where he played for two seasons. He had a successful stint with the Brewers, helping the team reach the National League Championship Series in 2011. Marcum had a career-best season in 2011, finishing with a record of 13-7 and an ERA of 3.54.

After his time with the Brewers, Marcum signed a one-year contract with the New York Mets in 2013. However, he struggled with injuries during his time with the Mets, making only 14 starts and finishing with a record of 1-10 and an ERA of 5.29.

Marcum then signed a minor league contract with the Cleveland Indians in 2014 but was released before the start of the season. He then signed with the Triple-A affiliate of the Los Angeles Dodgers but was released again after just one start.

In 2015, Marcum signed a minor league contract with the Cleveland Indians and played for their Triple-A affiliate, the Columbus Clippers. However, he struggled with injuries and was released by the team in July 2015.

Overall, Marcum had a successful career in MLB, finishing with a career record of 61-48 and an ERA of 3.93. He was known for his ability to change speeds and keep hitters off balance, as well as his competitiveness on the mound. Despite his struggles with injuries towards the end of his career, Marcum remains a respected figure in the baseball community.