The Boston Celtics announced Tuesday that Al Horford has tested positive for COVID-19.
Horford currently is in isolation and has been ruled out for Wednesday's preseason game vs. the Orlando Magic. The veteran big man's positive test comes four days after his Celtics teammate Jaylen Brown tested positive for the virus and entered quarantine.
Brown is likely to miss the rest of the preseason, but the hope is he will be ready for the team's regular-season opener. Horford's availability for the Oct. 20 matchup vs. the New York Knicks is in question.
Also ruled out for Wednesday's preseason game are Josh Richardson, Dennis Schroder, Marcus Smart and Jayson Tatum as Boston gives its key players a rest.
Celtics vs. Magic is set for a 7 p.m. ET tip-off on NBC Sports Boston.