Four more members of the virus-stricken Miami Marlins have tested positive for Covid-19, US media reported Tuesday.
The Athletic website and ESPN both reported the additional Miami cases, taking the total number of Marlins players and coaches who have been infected with the coronavirus to 17.
There was no immediate confirmation of the new cases by either the Marlins or Major League Baseball.
The Miami outbreak has rocked baseball less than a week after the start of its abbreviated 2020 season.
The Marlins' games against the Baltimore Orioles scheduled for Monday and Tuesday have both been postponed.
The Philadelphia Phillies, who played the Marlins on Sunday, also saw Monday's game against the New York Yankees postponed.
Reports said that Tuesday's game between the Phillies and the Yankees had also been shelved.
The Orioles, who travelled to Miami for their two-game series against the Marlins without playing a game, are due to host the Florida franchise back in Maryland on Wednesday.
On Monday, MLB commissioner Rob Manfred said the Marlins' roster was undergoing further testing and that it was hoped the team would be ready to play again on Wednesday.
Manfred said the league had anticipated the possibility of an outbreak when it was designing safety protocols aimed at mitigating the risks of Covid-19.
"I think most of the owners realize that we built protocols anticipating that we would have positive tests at some point during the season, that the protocols were built in order to allow us to continue to play through those positives," Manfred said.
"I think there was support for the notion that we believe that the protocols are adequate to keep our players safe."
Manfred did not specify whether a team being laid low by the coronavirus would jeopardise the entire season.
"I think that a team losing a number of players that rendered it completely non-competitive would be an issue that we would have to address and have to think about making a change," Manfred said.
"Whether that was shutting down a part of the season, the whole season, that depends on the circumstances.
"Same thing with respect to league-wide; you get to a certain point league-wide where it does become a health threat and we certainly would shut down at that point."