Arena is the most successful coach in the league's history, having won a record five MLS Cups, including the first one ever in 1996 while at the helm of D.C. United.

The Revolution said it suspended Arena due to the MLS investigation into the matter.

"The organization takes any allegations of workplace misconduct extremely seriously and is working closely with the league and fully cooperating with its investigation," the Revolution said in a statement.

Arena could not immediately be reached for comment.

The New York native has twice coached the U.S. men's national team including at the 2002 and 2006 World Cup and led the team to three Gold Cup titles.

He joined the Revolution in 2019 and in his first four seasons with the club, they made three playoff appearances.