A player within the Sounders’ first-team roster has tested positive for COVID-19, the club announced Monday.

The player immediately self-isolated and underwent the medical protocols required by Major League Soccer, the Sounders said in a statement. The individual will remain in isolation until medically cleared and is being monitored by the club’s medical staff.

All other Sounders players and staff continued their daily virus testing. No other positive cases have been found, and none of those tested has symptoms, the statement said. The organization implemented contact-tracing procedures and determined the player in question was not in close contact with other members of the first team in the past week.

The last round of Sounders testing was completed Monday, clearing the club to meet Los Angeles FC in their Western Conference playoff opener Tuesday night at Lumen Field. The next round of testing will be Wednesday.

The positive test Monday is unrelated to the club disclosing a positive test among the coaching staff this month, the team said. Sounders forward Raul Ruidiaz also tested positive for COVID-19 in October while in Peru with his national team.

LAFC will be without four first-choice players Tuesday because of positive COVID-19 tests while with their respective national teams last week. Sounders defender Xavier Arreaga (Ecuador) is not eligible to play Tuesday because of an outbreak among his national-team teammates. A medical task force for MLS and the Players Association deemed it unsafe for him to rejoin the club.

MLS stated it would make an effort to reschedule playoff matches if a team returns positive tests that prevent it from playing. But if unable to do so, the club with the outbreak would be forced to forfeit, and the opponent would advance. If both sides have an outbreak, the team that finished the regular season with the higher points per game will advance.

MLS’s conference semifinals are slated to begin Sunday, and MLS Cup is Dec. 12.