The Marlins learned Sunday morning that their starting pitcher for the afternoon and two other players had tested positive for COVID-19 and would be unable to play.

An apparent coronavirus outbreak was underway in the visitors’ clubhouse at Citizens Bank Park and the Marlins responded by asking their shortstop to determine if the game against the Phillies would be played.

“He’s kind of an unofficial team captain of our club,” Marlins manager Don Mattingly said of Miguel Rojas. “He’s always texting the group and getting the feelings of the group. So when we’re dealing with situations or things, that’s usually who we’re working through.”

Major League Baseball issued a 113-page operations manual to all club employees before the start of the season. It outlines everything from on-field rules to testing procedures and what happens if a player tests positive. But Sunday afternoon, the status of the game amid a coronavirus outbreak was decided by a group text message among Marlins players.

“We made the decision that we’re going to continue to do this and we’re going to continue to be responsible and just play the game as hard as we can,” Rojas said.

» READ MORE: Yankees-Phillies game postponed as Miami Marlins suffer coronavirus outbreak during Citizens Bank Park series

But did the Marlins ever consider not playing?

“That was never the mentality,” Rojas said. “We knew that this would happen at some point. We came to the ballpark and we were ready to play. That was never our thought that we weren’t going to play.”

The opinion shared in the group chat was the same as the opinion of the Marlins organization, as both parties thought the team took enough precaution to play Sunday. Those opinions were then provided to the joint committee of Major League Baseball and the players union, which has day-to-day oversight of the monitoring and testing plan.

“There was testing on Friday, one positive on Saturday, testing again on Saturday, and the three additional positives on Sunday,” MLB commissioner Rob Manfred said on MLB Network. “What then happened, under the protocols, was we did contact tracing on all four positives. There were, I think, a small number of players who met the CDC guidelines. They were quarantined. We did additional testing. We did symptom checks. We did temperature checks and decided to proceed with the game on Sunday.”

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The operations manual says that after a player tests positive for COVID-19, the club must conduct contact tracing to identify the individuals who had close contact with the infected individual. The Marlins flew together to Philadelphia from Atlanta, traveled by bus to a Center City hotel, traveled by bus to the ballpark, dressed in the clubhouse, and sat in the dugout.

It could be easily argued that every Marlins player and staff member came in close contact over the weekend with the infected players. Manfred said “there is a distance requirement along with a duration requirement” by the CDC to define “close contact.”

If the individuals came in close contact, the operations manual says those individuals should be quarantined or isolated pending the results of an Expedited Diagnostic Test, which the Marlins received Sunday morning. Instead of quarantining and thus postponing Sunday’s game, the Marlins played a 3-hour, 44-minute game against the Phillies and then learned Monday morning that eight additional players had tested positive.

The Phillies were alerted Sunday morning about the Marlins’ situation and sent a text message to their players. They didn’t know exactly which Marlins players were positive, but they told their team to take precautions. Bryce Harper wore a mask when he ran the bases. Rhys Hoskins had a mask on when he played first base.

But the Phillies never considered not playing. Manager Joe Girardi said he thought the Marlins “followed protocol.” Harper said the Phillies do “all the things the right way to hopefully not contract that.”

So they played Sunday, but can’t play Monday.

» READ MORE: Sports world reacts to Marlins COVID-19 outbreak and its impact on potential NFL and college football seasons

The game against the Yankees at Citizens Bank Park was postponed and the operations manual has that covered. Postponed games, the manual said, should be continued at a later date. It doesn't have to be decided by a group chat.

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“We’re always concerned,” Girardi said. “I think you see our guys take precautions on the field. The good thing is when we do see players from the other team, it’s on the field and outside. There’s usually a lot of distance. So you hope that that protects our club. The problem is when somebody gets it inside your clubhouse that’s aware of it for a day or two and then has the ability to spread it around to a few people. It sounds like that’s what happened there.”