Players are divided into five groups with staggered schedules for weight-lifting and training.
The Texans head coach and general manager called scheduling "a monumental task" but players will put on pads and start playing real football on Aug. 14.
The first team meeting inside the practice bubble at NRG was held Thursday. The first couple of weeks will be a lot of strength and conditioning and walk-through work.
Until that point, they continue to be educated by health professionals on the virus and how to prevent its spread.
All Texans players who reported to NRG Stadium over the last three days have tested negative for the coronavirus, O'Brien said Friday.
O'Brien also seemed encourage by the investment made by the McNair family in transforming NRG Stadium.
He called it the cleanest building in Houston and joked that you could even eat off its floor.
"We do obviously anticipate, it's such a transmittable disease. That's what concerns you," O'Brien said. "But I do believe our players understand how important it is when you leave the building to continue to be very mindful of the disease -- mask wearing, social distancing and all of those things. I think we have a really good veteran team that understands that. We're ready. We talk about it all of the time. If someone, or a certain amount of people were to contract it, unfortunately that may happen. We have to be ready for that. We talk about those scenarios all of the time, but so far, so good."
It was not clear how many of the Texans players have reported for training camp. Only defensive tackle Eddie Vanderdoes has publicly opted out of the 2020 season, though it was unclear
Players are being tested every day, and there's even testing available to their family members, O'Brien said.
"I just think that’s what 32 teams are dealing with," O'Brien said of the challenges coaching during the pandemic.
"So far for us, over the last three days, we’ve had 100 percent negative tests, which I think is a testament to our staff and our players that they’re obviously taking this thing seriously. Our building has been basically redone, refurbished in every way, shape or form. You’ve got three different locker rooms we’re using. The cafeteria is redone, new flooring, everything. So I feel like we’re headed in the right direction."