NEW YORK (AP) — Seven St. Louis Cardinals players and six staff members have tested positive for COVID-19, causing Major League Baseball to postpone the team’s four-game series at Detroit.

The series was to have been played at Comerica Park from Tuesday through Thursday.

"You think about how quickly something like this can spread," Cardinals general manager John Mozeliak said. "Until it touches you, you sometimes might not believe it, but needless to say we know this is very real and we know it moves quickly and it moves silently, but it can infect a lot of people fast."

Mozeliak said that five of those who tested positive did not show symptoms. Mozeliak said the others did — headaches, cough, sniffles, low-grade fever.

"And of those eight, it's a variety of symptoms but nothing at this point requiring anything like hospitalization,' Mozeliak said.

St. Louis has been in quarantine since Thursday in Milwaukee, where the Cardinals' last series was also postponed due to positive tests. While all the members of the Cardinals' traveling party who tested positive have been returned home, the rest of them remain isolated in their Milwaukee hotel rooms.

The team is being tested daily.

“The hope would be to travel back to St. Louis Wednesday morning, work out Wednesday afternoon and allow players to get their feet moving again, their bodies moving again,” Mozeliak said. “And then on Thursday have a more robust workout and then play Friday.

St. Louis last played July 29 at Minnesota and is tentatively set to resume its schedule this Friday at home against the Chicago Cubs.

Mozeliak said he wasn't sure how the team might reschedule some of these games that have been wiped out with two series getting postponed.

"I haven't really even thought about our schedule much other than hopefully playing Friday," Mozeliak said. "It's hard to think about the future when you're literally trying to just get through the day."

The Cardinals are the second team sidelined by the novel coronavirus since the season started July 23.

The Miami Marlins are set to resume play Tuesday in Baltimore following an outbreak in their traveling party that sidelined half the players. Miami has not played since July 26.

Because the outbreak occurred in the visiting clubhouse at Citizens Bank Park, the Phillies were sidelined for a week while they were tested daily.

In another virus development, the Field of Dreams game in Iowa was postponed until 2021. The game at a new ballpark on the cornfield adjacent to the site of the 1989 movie had been planned for Aug. 13 in Dyersville.

The Chicago White Sox originally were to host the New York Yankees, who were replaced by St. Louis because of MLB’s new schedule. The White Sox will be one of the teams next year. The opponent has not been determined.