The 2020 Major League Baseball season didn't make through a full week of play before one club suffered a coronavirus (COVID-19) outbreak. As of Thursday, the Miami Marlins have 19 total positive cases, including 17 players that have tested positive for COVID-19. The Marlins outbreak had ripple effects on the season, including a revised schedule for Miami and four other teams.

After a conference call between commissioner Rob Manfred and the MLB owners, the league did not announce any plans to cancel or pause the 2020 season. Instead, Manfred said that they were double down on the health directives for players and coaches. As comprehensive as the league's 100 page-plus health and safety manual is, it does not provide any guidelines for a team outbreak. According to ESPN's Jeff Passan, the league will require every team to travel with a compliance officer who ensures that the team staff and players adhere to the league's health and safety protocols. 

Although the league is investigating the cause of the Marlins' outbreak, it could figure to be near to impossible to determine where, when and how the virus was brought into the team. According to the CDC, the incubation period (the time from exposure to development of symptoms) of the coronavirus ranges from 2–14 days. Here's more from Passan regarding the league's investigation into the Marlins COVID-19 outbreak:

The investigation is looking into a wide range of factors, from the team's in-stadium behavior -- mask wearing, social distancing and other protocol-suggested factors -- to the off-field activities of players and staff, according to sources. The league will especially probe the veracity of players going out at night in Atlanta during the Marlins' time in the city for preseason games against the Braves. However much the actions of those in the Marlins' organization might have tested the protocol by not adhering to it, what happened Sunday highlights gaps that warrant more attention.

Following the positive tests of starter Jose Urena, first baseman Garrett Cooper and right fielder Harold Ramirez, the protocol called for contact tracing -- a look into which other players or personnel fell within Centers for Disease Control and Prevention guidelines of "close contact": being within 6 feet of an individual for about 10 minutes, according to a copy of the protocol obtained by ESPN.

In the league's health and safety manual, no specific rules were outlined for players when they are away from the ballpark. Instead, the league decided to rely on them making responsible decisions. The updated rules, including an addition of a COVID-19 compliance officer, were outlined in a memo sent to all MLB teams on Tuesday, Passan adds.

MLB became the first professional sports league to commit and move forward with a return-to-play plan that included traveling. Other pro American sports leagues, like the NWSL, NBA, MLS and WNBA, have chosen to host players in a one-location "bubble" for their respective seasons. In the NBA's bubble set-up in Orlando, zero players have tested positive for COVID-19 for the second consecutive week. Marlins outfielder Harold Ramirez, who is one of the team's players with COVID-19, recently said that he believes switching to a bubble plan for the remainder of the 2020 season would be a good idea.