He also posted a video on his Instagram account from his hotel room at the Walt Disney World Resort, via Ohm Youngmisuk of ESPN.
The forward referenced his grandmother in a tweet Monday:
"Losing my grandmother has changed everything in me everything, life, living people, everything," he also wrote in an Instagram story post.
Clippers head coach Doc Rivers was understanding of the grieving process, letting Harrell take his time in returning.
"When he's ready, he'll come back," Rivers said earlier this month, per Youngmisuk. "You can't play if you're not right mentally and because of the emotional part of it. ... His grandmother is very tight with him so all I told him is I love him and take your time. We'll be ready with open arms when you come."
Now that he has returned, Harrell will now have to quarantine for at least four days before he can step on a court, as long as he continues to test negative for the coronavirus.
It's unknown if he will play in the final seeding game Friday against the Oklahoma City Thunder, but he should be available for the start of the playoffs. The Clippers currently have the No. 2 seed in the Western Conference.
Harrell's return is huge for Los Angeles as it adds the team's most reliable post presence. The Sixth Man of the Year finalist is averaging 18.6 points, 7.1 rebounds and 1.1 blocks per game, providing excellent balance alongside perimeter stars like Kawhi Leonard, Paul George and Lou Williams.
Getting the rotation back to full strength should make the Clippers a top contender to bring home a championship this summer.