[2] After graduating from high school in 1990, he moved to Germany and signed with SC Freiburg, spending a season with the reserve team before returning to the United States.

In February 1996, D.C. United selected Lagerwey in the 15th round (150th overall) of the 1996 MLS Inaugural Player Draft.

In 1997, he moved to the Dallas Burn where he played only ten games over two seasons before being waived on October 31, 1998.

[5] He then signed with the Miami Fusion where he played mostly as a backup, but still entered 18 games to replace Jeff Cassar during injury spells.

[7][10] On September 19, 2007, Real Salt Lake (RSL) announced Lagerwey was hired as the team's senior vice president and general manager, reuniting with Duke University teammate Jason Kreis, who had been named head coach in May.

[11][12] He was hired by Dave Checketts through his attempt to sell a stake in the St. Louis Blues hockey team, which was handled by Latham & Watkins.

[8][13] Lagerwey left RSL in December 2014 after seven seasons and moved to conference rivals Seattle Sounders FC amid other offers from MLS clubs.