The 2020 MLB season has begun but COVID-19 concerns are not going away. On Saturday, the Cincinnati Reds lost Matt Davidson to the COVID-19 injured list, one day after he was in their Opening Day lineup. The Miami Marlins are reportedly also dealing with at least one positive test in their clubhouse.

The Marlins, who had four unnamed players test positive for the virus in summer camp and placed catcher Jorge Alfaro on the injured list for an undisclosed reason earlier in the weekend, scratched righty Jose Urena from his scheduled Sunday start in Philadelphia.

MLB Network's Jon Heyman reports that Urena tested positive for COVID-19, as did outfielders Garrett Cooper and Harold Ramirez. Add in Alfaro and that's three starting position players plus a rotation piece.

Marlins manager Don Mattingly also confirmed the team would not be traveling back to Miami from Philadelphia until Monday -- the same day the Marlins host the Orioles in their 2020 home opener. It appears the team is awaiting another round of COVID-19 test results. 

Not long after the Marlins scratched Urena, Reds manager David Bell announced infielder Mike Moustakas woke up feeling ill and was being isolated away from the team. "We're just being overly cautious ... If there's any doubt, we stay home," Bell said, according to's Mark Sheldon. Moustakas was placed on the injured list soon thereafter.

Furthermore, Nick Senzel was a late scratch from Cincinnati's lineup on Sunday. Bell confirmed he also was "not feeling well." The Reds have not yet placed Senzel on the injured list. 

The obvious concern is multiple players on one team either testing positive or showing symptoms in rapid succession, like Davidson (tested positive) and Moustakas and Senzel (potentially showing symptoms). Florida currently has the second most COVID-19 cases of any state, and even though the team is currently on the road, the Marlins held summer camp at home in Marlins Park. 

MLB created a new COVID-19 injured list this season and it can be used when a player tests positive, shows symptoms, or has contact with someone known to have tested positive. There is no minimum or maximum stay on the COVID-19 list and players must test negative twice at least 24 hours apart to be activated, among other things.

Because COVID-19 is a non-work-related illness, it is subject to the privacy guidelines in the collective bargaining agreement. A team can not discuss COVID-19 without without the player's permission. Thus far the majority of players have granted approval to discuss their situation, like Davidson. Some have not though.

The Operations Manual, the 100-plus page document outlining the league's health and safety protocols, requires players to wear a mask at all times except when on the field or working out. Players are tested every other day and results are expected within 24 hours, though there have been delays around the league these last few weeks.

Nationals slugger Juan Soto is the most notable player to test positive for COVID-19 since Opening Day. There is some thought his test result could be a false positive, though the club was still awaiting official MLB testing results as of Sunday morning.