The latest positive test is the ninth such result that the Crew has sustained during the postseason.
A total of eight players missed at least one match during team's run to the final due to the positive test results, but the Crew said in a statement that six of those players have returned to training. A source with knowledge of the situation said that a seventh will resume practicing on Thursday.
Addressing the latest round of tests, the Crew statement added that "no additional confirmed positives for players or staff were returned following two days of testing results on Monday and additional testing results returned Tuesday night."
In a bid to minimize the chances of additional spread, the team has restricted indoor access to the training facility for players to limit interaction to on-field training.
Columbus is scheduled to train Wednesday through Friday.