Four Miami Marlins players have tested positive for the coronavirus, including Sunday's starter, Jose Urena, according to sources familiar with the situation.

The Marlins will be without the services of catcher Jorge Alfaro, who was placed on the injured list before their season opener on Friday, as well as Urena, infielder Garrett Cooper and outfielder Harold Ramirez.

The news of the positive tests was first reported by baseball writer Robert Murray.

It's possible the infections occurred on the team's trip to and out of Atlanta on Wednesday, where the Marlins played the Braves in an exhibition contest. Since leaving Atlanta -- after a flight delay -- Miami has been in Philadelphia all weekend for the team's opening series of the season.

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.

Right-hander Robert Dugger started in Urena's place Sunday.