One Rapids player and three staff members returned positive tests, which were administered Thursday and Friday.
A statement read: "Based on the number of positive test results, Major League Soccer has postponed the match to allow for additional testing and evaluation."
The league added that all other members of the Rapids returned negative results.
It's the first time that COVID-19 has impacted a match since the MLS regular season resumed in August. Toronto FC's game against D.C. United at the MLS is Back Tournament in July was delayed due to uncertainty over test results for two players.