NEW YORK -- The Yankees' post-All-Star break opener against the Boston Red Sox on Thursday night was postponed because of positive COVID-19 tests within New York's organization.

Major League Baseball said the postponement was to allow for more testing and contact tracing.

The Yankees have three positive tests for COVID-19 with three tests still pending, according to general manager Brian Cashman. All the positive and pending tests are from Yankees players.

New York was among the first major league teams to reach the 85% vaccination threshold to lessen coronavirus protocols such as dropping mask use in dugouts and bullpens.

The Yankees placed left-handers Nestor Cortes and Wandy Peralta on the COVID-19 injured list Thursday around midday.

New York players were on the field taking early batting practice about 3 1/2 hours before the scheduled start when the Yankees asked media to leave the field while the team conducted COVID testing.

Boston came onto the field as the postponment was announced to take batting practice.

This is just the eighth game postponed due to COVID-19 this year and the first since April 19 (Twins-Athletics). There were 51 postponements due to COVID-19 last year.

The Associated Press contributed to this report.