After serving as an assistant coach at Wesley College for six seasons, Bret Underwood was promoted to head coach in January 2011. Before being promoted, Underwood primarily worked with the hitters and infielders while coaching first base.

Underwood's first season at the helm in 2012 was a banner year for the Wolverines as they won a program-record 31 games and hosted the ECAC South Tournament.  After defeating three nationally-ranked opponents on the season, Wesley had a CAC-leading five players earn All-Conference honors, including the program's first-ever CAC Player of the Year in Rob Benedict. Four players also earned All-Region honors, including Geoff Kimmel and DJ Keckler who set several Wesley single-season marks on the way.

An assistant from 2006 to 2011, the Wolverines made its Conference playoffs each season, won the ECAC South Region title in 2010 and enjoyed the winningest six-year run in school history at the time (157-92-1, .630).

A four-year starter at Delaware State University at first base, Underwood was one of the most prolific hitters in school history and was named first team All-MEAC in his three final seasons. He still holds the Hornets career record for hits (272), while ranking in the top three in home runs (50), runs batted in (224), runs scored (185), and extra base hits (107) while hitting .354. As a sophomore, he finished 19th in Division I with 77 RBIs, which is also a school-record.

After completing his senior year at Delaware State in 2004, he signed a free agent contract with the Boston Red Sox. Underwood attended Dickinson High School in Wilmington, Del., where he was a two-time all-state selection.