At age three he began taking hacks. At age six he enrolled in flag football.
A dual-sport star, Ruiz is a playmaker on both La Puente Bishop Amat's baseball and football teams.
At 14 he verbally committed to play baseball at USC.
But this was two years before his greatest accomplishment: At 16 he hit a two-run home run in the Southern Section Division 4 championship game at Dodgers Stadium. Just sixteen years old, Ruiz had already homered at a major league ball park.
A year later, the Trojans' football team expressed interest in Ruiz, enough to ask him to consider both sports at the next level.
Rio Ruiz had no doubts about choosing USC to go to college and has no doubt he wants to help both programs get back to the level of excellence he saw growing up.
"I just want to help them in any way I can," Ruiz said. "If they think I am not fit to be somewhere at a certain point then they're going to transition me to something else. Whatever they do I know it's going to benefit them and that's all I'm there for."
More astonishing than any of his young accomplishments, though, is his mature mind.
"If this game ends for me at some point-- I hope to god it doesn't-- I feel that I made people happy doing the thing I love," Ruiz said.
Nearly 14 years of baseball under his helmet and he's already talking about the impact he'll make when he's done. Most adult athletes don't understand the role he or she can play in another's life but Ruiz already gets it.
"Rio brings an enthusiasm to the team. He refuses to lose and it spreads to the other guys," Joe Canales, one of the Lancers defensive coaches, said. "Everything he does he does it 100 percent, to playing out here to playing baseball, and we feed off of that."
Huge contributors to this mindset are his parents, clearly. His dad, a waste management manager, has been his coach and trainer since those early years. His mom, an employee for Southern California Edison, has raised four kids, including Rio.
"I could count the number of games of mine they've missed on one hand," Ruiz said.
That unofficial record includes football game attendance, where Ruiz plays both quarterback and safety for Bishop Amat. In Thursday's 38-35 win over Venice High, Ruiz completed 16 of 24 passes to help the Lancers amass a 5-1 record. The dual-threat signalcaller did not get intercepted once but he did record the only takeaway of the evening, picking off the opposing quarterback just minutes after he was the one under center.
"He could have just stuck with baseball but he loves the game of football, he loves the Friday Nights, he loves the fans and this is what makes him happy," Canales said.
The big man on Amat's campus, Ruiz understands that he still has a lot to learn. But he knows he's in a position right now where even younger kids than himself look up to him, see the college he plans to attend and the success he's had, and view Ruiz as their idol.
"I make them feel like I'm a normal kid just like they are. I just work hard and I love doing what I do but you just got to be you, you can't try to be somebody else," he said.
Ruiz still has his superstitions, like most athletes. But you're reminded he's just a kid when he opens a pack of gummy bears before each game he plays and stuffs them into his mouth.
He said it's a habit he's been doing forever, but it really hasn't been that long.
Just 17 years old, Ruiz has all the tools to have a successful future at USC and beyond.
Because, well, he's well beyond his years.