The club was renamed Sockers and choose to be relegated to the amateur USL Premier Development League (PDL), the fourth tier of the American soccer pyramid, for the 1999 season.

The Sockers were one of the most successful amateur teams in the late 1990s, winning three national titles including back-to-back PDL Championships in 1999 and 2000, reaching two divisional playoffs, and getting to both the quarterfinal and semifinal of the US Open Cup prior to 2000.

The Sockers were Champions again in 2000 after a move to the Heartland Division, finishing first in the regular season and defeating the Mid-Michigan Bucks 1–0 in the Championship final.

The PDL amateur club defeated an MLS side, Kansas City Wizards, in a hard-fought penalty shootout after a 0 - 0 overtime score.

The Sockers came close to a similar upset of an MLS team in the third round but fell short, 1 - 0 to the eventual U.S. Open Cup champion, Chicago Fire.