Harrell also posted a video to his Instagram account, which he appears to have taken from his hotel room.
Harrell left the Disney World resort on July 17 for an emergency family matter. During his absence, he announced that his grandmother had died.
Before he can rejoin the Clippers for team activities, Harrell must quarantine for at least four days. Los Angeles plays its next game Wednesday against the Denver Nuggets before concluding its seeding games Friday against the Oklahoma City Thunder.
Following his team's loss to the Brooklyn Nets Sunday, head coach Doc Rivers did not confirm if Harrell would be available before the start of the postseason.
"We don't give out that information," he said, according to The Athletic's Jovan Buha. "But we hope so, that's all I can say."
Harrell, a finalist for the 2019-20 Sixth Man of the Year Award, is averaging 18.6 points and 7.1 rebounds this season for the Clippers but hasn't played in any of the team's seeding games in Orlando.
After announcing his return to the NBA campus, he appeared to dedicate the rest of the season to his late grandmother.