Even though he could be activated to practice anytime, the indefinite timing could have become uneasy for Texans fans.
But on the field on day one, there he was. With his "99" emblazoned in all of his glory, Watt had pads and a helmet on and participated.
Speaking to the media, Watt even expressed surprise over his activation.
- Popular Texans players to begin training camp on sideline
- Here's when you can watch Houston Texans training camp
- Houston Texans reveal 2019 season schedule
- Houston Texans face off with all NFC teams in 2019 preseason
"Yeah, it surprised me a little bit too," said Watt, who had arthroscopic knee surgery in January. "I feel great. I had a really good off-season working with the guys. Just really happy to be out here."
On top of welcoming Watt on the field, the Texans also enjoyed outdoor conditions unlike past Houston summers.
"If we get this weather every day, that would be great," Watt said of the low humidity and mild temperatures.
Once Houston conditions return to the practice field, Texans players are expected to make great use of a cooling recovery zone.
According to head coach Bill O'Brien, players can go in a room for a few minutes during practice to help them stay fresh and recover. The feature was pushed by team chairman Cal McNair.
While the weather wasn't annoying by Watt's standards, Watt's defense proved to be annoying to the offense, at least according to QB Deshaun Watson.
No. 4 said Watt and his side of the ball disrupted some of the passes coming out of his cannon arm.
"It's annoying," Watson said with a smile. "He tipped two or three balls of mine today."
Watson pointed out that those disruptions appeared to come from O'Brien's new approach to defense this season.
The Texans were without wide receiver Deandre Hopkins, who has been dealing with ankle and shoulder injuries from last season, and Justin Reid, who was involved in a rear-end car accident just days before the start of camp. Reid's injury issues are not believed to be serious.
Most glaring of the absences Thursday was Jadeveon Clowney, who, as expected, did not report amid negotiations of a long-term contract. The Texans designated him as their franchise player, which tenders him a one-year deal.
While declining to talk about any discussions with Clowney, O'Brien expressed hope to have him on the field sooner than later.
"I can tell you unequivocally that we want Jadeveon Clowney here," O'Brien said. "He's a part of this team. We want him here. There's always a difference when you're talking about money relative to wanting him on the team. That's something that the agent and our organization are working on, but relative to the player and the history that he and I have together, we would love to have him here. He's a really talented football player that's made a lot of good plays for us in the past, and like I said, the sooner the better. I'd love to have him here."
Follow the Eyewitness Sports team on Facebook: