Webster grew up in Baltimore, Maryland, playing three years of varsity lacrosse at the Boys' Latin School before heading to South Bend to play for the Notre Dame Fighting Irish where he started at attack, earning four titles in the (now-defunct) Great Western Lacrosse League and four NCAA tournament appearances, before graduating in 1999.

Prior to Cal, Webster spent nine seasons as head coach at Dominican University, transforming a winless club team into a nationally ranked NCAA DII program, leading his teams to back-to-back Western Intercollegiate Lacrosse Association (WILA) Championships in 2013 and 2014, the same two seasons he was named WILA Coach of the Year.

Webster spent two years as an assistant coach for the MLL's San Francisco Dragons, the Bay Area's former professional lacrosse franchise, coaching the offense and working with the goalies.

Webster comes from a lacrosse family: his father Mickey was a Hall-of-Famer and National Champ at Johns Hopkins, while his brothers, Jim and John, played lacrosse at University of Virginia and the University of North Carolina, respectively.