The San Francisco Giants divisional clash with the San Diego Padres was abruptly postponed on Friday after a member of the Giants organization tested positive for COVID-19, the team announced.
The postponement was confirmed shortly before the Giants' game at San Diego's Petco Park was due to get under way.
"Tonight's game was postponed due to a positive COVID test within the Giants organisation," the Giants said in a statement.
"Major League Baseball will announce additional information regarding the status of our series with San Diego as soon as possible."
More than 40 MLB games have been postponed this season due to positive coronavirus cases.
The baseball was due to start in March but eventually got under way in July with an abbreviated 60-game season due to the COVID-19 pandemic.
The Giants are third in the National League West rankings with a record of 23 wins and 22 defeats.
They trail the Padres in second place (29-17) and the Los Angeles Dodgers, who lead the division with a 32-13 record.