The Rockets have not disclosed a reason for Harden's delayed arrival.
Russell Westbrook, Houston's other All-Star guard, announced Monday that he tested positive for COVID-19 before the Rockets departed for Orlando. The Rockets hope that Westbrook, who must test negative twice before he will be cleared to enter the NBA bubble, will be able to travel at some point this week.
A Rockets source told ESPN on Tuesday that there is no set day for Westbrook's travel.
Harden must go through an initial quarantine period in his hotel room, as all players and staff did upon arrival, before joining the Rockets for practice.