Their dad, Randy, often coached Wes' teams, and Ryan, now an infielder for the Chicago Cubs, was the bat boy. If somebody didn't show up, Ryan, who was five years younger than Wes, got to play.
The two were active in the backyard of their Baton Rouge, La., home, along with their younger brother, Austin. And dad was there to support the boys.
"He was a great friend to have helping us get better," Ryan said of his father. "It really didn't matter what sport it was. It wasn't all baseball. It was all sports. We played all sports together."
It's nice to hear a son refer to his dad as a friend, especially on Father's Day.
"You know why? He wasn't the type of father who pushed anything on you," Ryan said. "Never once did he have to come up to me and say, 'Let's go outside and work on this, let's go work on that. You need to do this, you need to do that.' It was always more encouragement. I had the feeling that if I went outside to do something by myself, he'd come out to help me out with it.
"I've watched parents who push their kids, because they want them to do so much," Ryan said. "To his credit, he wanted us to succeed, but he never pushed it on us, and I think it made me more hungry."
Randy Theriot was never Ryan's head coach when he was growing up. That was OK by Ryan.
"I think he knew it was best for him to stay away, so no one would think he was playing favorites," Ryan said.
And when Ryan said that his father stayed away, he means it. Literally.
"He was a real fiery person," Ryan said of his dad, "so during the games, he wouldn't sit in the stands. He'd go down the left-field line and stand by himself. He never yelled, never screamed, never yelled at umpires.
"I definitely got my enthusiasm and fire from him. It's in him. Everybody thought he was really laid back. But when it was us two, and I did something wrong, he'd definitely let you know about it."
When Ryan found out he'd made the Cubs' Opening Day roster in March, he called his father immediately.
"The whole thing is a dream for all of us," Ryan said. "It's so cool to include him."
Randy Theriot is taking advantage of being in the big leagues through his son. In a game at Wrigley Field this year, Ryan was able to acquire an all-access pass for his father. Randy walked all around the ballpark, explored the visitors' locker room, the press box and talked to WGN Radio broadcaster Ron Santo for about 30 minutes.
"I said, 'What did you do?' and he said, 'I went everywhere,'" Ryan said. "He was like, 'Hey, you gave me the pass. I'm going to do it.'"
Father's Day has good memories for the Theriot family. In 2000, Ryan helped LSU reach the College World Series, and the event was held around Father's Day. Randy didn't miss it, but he was hiding in the bleachers watching his son, who was named to the CWS All-Tournament team.
"He's always hard to find," Ryan said of his dad. "He doesn't want to be in the middle of the commotion."
Not only is Randy Theriot a friend to his son, he's also a huge influence in how Ryan will raise his children. He has a son, Houston, 4, and daughter, Macey, 4 months.
"I'm going to try to be exactly like my dad was," Ryan said. "The thing is, you see kids growing up who are pushed and pushed and pushed to be a baseball player. It's not their dream, it's their parents' dream. The kid loves playing, but does he want to make the sacrifices to do it for a living? Probably not.
"In my case, there were tons of parties and fun things I missed out on in high school, because personally I made the sacrifice," he said. "It was never anything my dad said -- it wasn't, 'If you go to that party, you won't play well tomorrow.' He said, 'It's your decision. If you want to go, go. You might not be at your best tomorrow.' He put it in my corner. I was able to think through the consequences of doing certain things.
"He taught me at an early age to think through everything before you actually do it," Ryan said.
That lesson applies today in the big leagues.
"It applies to everything," Ryan said. "Yelling at the umpires, throwing your helmet, throwing your bat after you strike out -- you won't see me doing that very often. It was something I learned at an early age that there's consequences for your actions."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.