Prager attended
Princeton where he earned the 1999 Men's Ivy League Rookie of the Year and the
2001 NCAA Division I Men's Lacrosse Championship tournament Most Outstanding Player. His 25 goals as a freshman in 1999 was a Princeton freshman record. In 2010, Ivy League Rookie of the Year
Mike Chanenchuk totaled 28 as a Princeton freshman to surpass Prager's record. He served as co-
captain of the 2002 team. During his four years at university, Princeton won the Ivy League Conference outright each year, achieving undefeated 6–0 records in 1999–2001 and having a 5–1 record in 2002. while he was an honorable mention in 2001. He was a first team All-Ivy League selection in 1999, 2000 & 2002 and a second team selection in 2001. He was a 2002 USILA Scholar All-American. In 2000, Prager tore his
anterior cruciate ligament while he was the leading scorer with 23 goals in his first 8+ games and was lost for the remainder of the season. In the 2001 NCAA championship semifinals, Prager scored three goals against
Towson State in a 12–11 victory. In the finals, he scored a total of four goals, including the game-winning goal in
overtime with an assist from
Ryan Boyle as well as the ninth goal in the 10–9 victory over
Syracuse. In the
2002 NCAA Division I Men's Lacrosse Championship semifinals, he scored five goals in an 11–9 victory over
Johns Hopkins, but in the 13–12 finals loss, Syracuse defenseman Solomon Bliss held him to one goal. ==Professional career==