Several clubs made personnel moves to meet the 20-man roster deadline on March 28.
Colorado waived goalkeeper Dusty Hudock, who saw action in nine games last season.
San Jose waived former UNC Charlotte star Mac Cozier, who played for Columbus in 1996, and former MetroStar Edmundo Rodgriguez.
Tampa Bay placed Polish forward Jacek Ziober on injured reserve.
D.C. United waived forward Gerson Echeverry
Kansas City, desperate for defensive help with Diego Gutierrez, Sean Bowers, Steve Pittman and Scott Uderitz all injured, acquired defender John Diffley from Tampa Bay for a conditional third-round draft pick in 1999 or 2000. Diffley flew to Kansas City on March 28, and played the full 90 minutes in a 3-2 shootout win over San Jose the next afternoon.