The Rockets had their second workout of training camp on Monday and afterward the new coach addressed the absence of the disgruntled star who reportedly wants to be traded.
"As far as timetable, there's no timetable as far as I know," Silas told reporters when asked when Harden would arrive. "And it is a setback. You want your best player to be here. And there's a short window ... I have to be honest and understand this is a setback not having one of the best players in the NBA here."
Silas, who was hired to replace Mike D'Antoni, said he doesn't even know if Harden is in Houston and said the team hasn't discussed any possible penalties for the superstar if he doesn't report soon.
"I've been in situations before where it was a holdout, and we just kind of handled each individual situation on its own merit and individually," he said. "As far as any sort of punishment, we haven't even crossed that bridge yet. We're just trying to work piece by piece."
The Rockets are intent on keeping Harden as the centerpiece of their team. They shipped Russell Westbrook to Washington last week in exchange for John Wall after Westbrook's one-year pairing with Harden didn't pan out.
Silas isn't sure why the eight-time All-Star and 2018 MVP is not at camp and wouldn't speculate about the motivation for his absence.
"What the reasoning is, is on him," Silas said. "He's the one who can explain why or why not he's here. For me to make inferences and think about the possibilities isn't real to me. What's real is he's not here and he has a reason, but that's on him to tell whoever what his reason is."