As a player, he was listed at 5 feet 9 inches (1.75 m) and 175 pounds (79 kg) while batting and throwing right-handed.

[3] After five seasons in the Royals' farm system, a knee injury led to the end of his playing career.

[3] In 2006, Rutgers manager Fred Hill asked Fenster to serve as a coach for the Scarlet Knights.

[6] Fenster became the Red Sox' minor league outfield and baserunning coordinator before the 2019 season.

[7] In February 2022, Fenster was named minor league infield coordinator for the Red Sox.