HOUSTON — Before Deshaun Watson led Clemson to a national championship or the Houston Texans on game-winning drives, he was a nervous 13-year-old ball boy for the Atlanta Falcons.

The summer before Watson’s freshman year at Gainesville High School in Georgia, he spent his August with the Falcons at their practice facility in Flowery Branch — just 10 minutes from his home. He picked up balls during practice, took care of the equipment and folded towels, among other things.

“Anything that the players needed, we took care of it,” said Watson, whose Texans will play the Falcons for the first time since he was drafted on Sunday (1 p.m. ET Sunday, Fox).

One of his other tasks, after he was assigned to the wide receivers and quarterbacks, was throwing to the receivers during drills for then-Falcons receivers coach Terry Robiskie.

“He would throw to Eric Weems, Harry Douglas, Andrew Davis, and when he would throw to my ‘no-name guys,’ and he would hit them all in the chest, throw the ball right in their face,” said Robiskie, who is now the running backs coach for the Jaguars. “Just perfect balls, you know what I mean? And then all of a sudden, Roddy White would step up, or Julio Jones would step up, and he’d throw it in the ground.”

“We used to give him a hard time when he threw bad balls,” White said. “I was like, ‘How you supposed to be that good and you throwing damn bad balls?’ And he was like, ‘You guys make me nervous.’ And I was like, ‘How you nervous? We’re at practice.’ And he would be like, ‘It’s different throwing to high school players and throwing to you guys.’”

“That first year I was a little nervous because I wanted to be perfect,” Watson said. “I wanted to make sure they were getting the right balls thrown to them and everything like that.” But those nerves went away quickly, and Watson “was just cutting it loose.”

“They were like, ‘OK, now I see what all these schools are talking about,’” Watson said. “It became fun, and we became cool.’”

Watson got the job through the Boys & Girls Club in Gainesville, one of a few high school students chosen to take part in the program that was started by Falcons owner Arthur Blank. Along with helping during training camp, the team let the ball boys be on the sideline and in the locker room on game days. “We got the whole NFL experience,” Watson said.

Watson did such a good job, he was asked back by the Falcons each year that he was in high school. Suddenly, the 13-year-old who was nervous about throwing to NFL receivers was putting together an excellent high school career, and by the time he was a sophomore, he had committed to Clemson. Spending all that time around the team and players, Watson said, “taught me how to really work.”

“I always think about it,” Watson said. “That’s something that helped change my life. Especially during the times off the field … the way I was raised and the environment I was living in. It helped me see another side of what I can be and what I can become. And being around professional athletes and guys I’m going to play against Sunday, it really helped me get to where I am today.

“It had me see a different perspective on the game and how I take care of my body and how I need to really approach each and every day, especially in practice. Everything was crisp, everything was sharp, everything was on time. And no balls really touched the ground. So that’s what I wanted: to try to perfect my craft at a young age and bring my game to another level.”

Watson also learned how he wanted to treat people. During training camp one year, cornerback Asante Samuel was doing a special teams drill when he realized he forgot his mouthpiece in his locker. He asked Watson to go get it for him. After Watson brought it back, Samuel told him to come find him after practice.

“So I went to his locker after practice, and he pulled out his Louis [Vuitton] bag and pulled out a whole stack of money, and he gave me like $1,000, just to go get his mouthpiece,” Watson said. “He didn’t have to give me anything, but he did.”

During his time with the Falcons, Watson was winning games for Gainesville High School, where he set school records, and won the state championship his junior year. On some Fridays, Robiskie, Weems and Douglas would go to Watson’s games to see their ball boy play. Falcons quarterback Matt Ryan said the team would follow to see what Watson was doing on Friday nights, and they’d talk about it when they came in on Saturday mornings.

“S—, I knew he was a hell of a quarterback,” Jones said. “I tried to get him to go to Alabama.”

“He told me he was going to win a national title,” White said. “He said he was going to change the culture. We wanted him to go to Bama, and he said he was going to beat Bama.”

When Watson was a ball boy, he learned by observing everything around him, but according to Robiskie, “he wasn’t talkative” or “all that stuff he is today in Houston.”

“He was cool, man, but he was the quietest dude I’ve ever been around in my life,” White said. “He didn’t say two words. I always told him, ‘If you never talk, how are people supposed to know who you are?’

“‘And he was like, ‘I’m just out here on the grind.’”

Watson is looking forward to his homecoming. He has already traded texts with Kenny Osuwah, who is still an equipment manager for the Falcons, and is looking forward to talking to Ryan before or after the game.

“I know a lot of those guys sit there and watch him and, like me, they’re just amazed at how far he’s come and where it all came from and where it all started,” Robiskie said. “And we all see that little guy who stood there that day, and when Roddy and Julio came up, he couldn’t throw it 10 yards. But eventually he got it, and boy, did he get it well.”

And while Watson is anticipating seeing some familiar faces on Sunday, he’s also excited for those guys to see what became of that once-nervous 13-year-old who learned so much from running around the team facility.

“It’s cool for them to be able to see that I became the person that they thought I was going to be able to become,” Watson said.

ESPN Atlanta Falcons reporter Vaughn McClure contributed to this story.