That's up from the four players who had tested positive as of Sunday.
The team wrapped a series against the Phillies on Sunday at Citizens Bank Park, and were set to fly home to Miami on Monday.
Updating the Miami Marlins’ outbreak: The total number of infected players is 11 of the 33 who have been traveling with the team and two coaches, sources tell ESPN.— Jeff Passan (@JeffPassan) July 27, 2020
The Marlins-Orioles and Yankees-Phillies games tonight have been postponed. For now, the rest may be played.
However, their flight home has been canceled, Action News has learned.
Major League Baseball announced the postponement of both Miami's home opener against the Orioles and the Phillies home game against the Yankees on Monday.
Commissioner Rob Manfred announced in an interview on MLB Network that the Marlins game against the Baltimore Orioles would be postponed.
Manfred also says that if the results from the additional COVID-19 testing are acceptable, the Marlins and Orioles will resume playing on Wednesday in Baltimore.
Commissioner Manfred sits down with Tom Verducci in Studio 21.— MLB Network (@MLBNetwork) July 27, 2020
Tune in to MLB Tonight after the game for the full interview. pic.twitter.com/WnZx8q5U8q
Under MLB guidelines, the players will be isolated from the team until they test negative twice at least 24 hours apart, show no symptoms for 72 hours, and receive approval from team doctors.
🚨 The Miami Marlins have cancelled their flight from Philly to Miami today @6abc has learned— Jeff Skversky 6abc (@JeffSkversky) July 27, 2020
Marlins were scheduled to fly to Miami Sunday after the finale vs Phillies but had postponed until today but now Marlins forced to postpone flight out of Philadelphia again#Marlins https://t.co/bRNf5Yoc1m pic.twitter.com/UydJ7R7oQ8
Phillies manager Joe Girardi said on Sunday the players were texted early in the day to know that a potential coronavirus outbreak had affected the Marlins.
"You have to be safe. You can't really be in contact with a lot of people because you put everybody in danger," he said.
Phillies manager Joe Girardi on his concern for his players and team after the Marlins reportedly have four players test positive for COVID-19 while in Philadelphia this weekend— Jeff Skversky 6abc (@JeffSkversky) July 26, 2020
“You’re always concerned” @6abc #Phillies #Marlins pic.twitter.com/VPlwmzyWKh
Jose Urena, Miami's opening day starter in 2018 and 2019, was bumped from his start about 90 minutes before the first pitch. The Marlins did not disclose the reason.
According to ESPN, Urena and three other Marlins players were the first four to test positive.
The Marlins did not consider sitting out Sunday's game.
"We're taking risks every day," Marlins manager Don Mattingly said on Sunday. "That's what the players all around the league are doing. You travel all the time .. it's a risk that we take. We're going to have to be adjustable, we're going to have to be flexible, we're going to have to be patient."
The Marlins' precarious health raised anew doubts about MLB's ability to finish the season during a pandemic. In Cincinnati, Reds second baseman Mike Moustakas and center fielder Nick Senzel felt sick Sunday, a day after a teammate went on the injured list because he tested positive for COVID-19.
The Marlins played exhibition games at Atlanta on Tuesday and Wednesday against the Braves, who have since been without their top two catchers, Tyler Flowers and Travis d'Arnaud, after both players showed symptoms of COVID-19.
Mattingly declined to say whether he thought the Marlins' health issues were related to the Atlanta stop. Miami is a hot spot for the pandemic, but on Sunday, Mattingly said he feels safer there. "You feel safe at the ballpark; I feel safe with my surroundings going home," he said. "It's a lot scarier on the road."
Just a short distance away from Citizens Bank Park, the Philadelphia Eagles and head coach Doug Pederson were getting ready for training camp at the NovaCare Complex.
Pederson said the plans and protocols put into place by the NFL and the Players Association gives him hope.
"The virus is real and and we do everything we can in our powers to stay safe protecting ourselves," he said.
ESPN and the Associated Press contributed to this report