Jennings remembers the trips in the family car, up to Wichita Falls and T-Bar Fields in Denison, Texas. Even from his home in Mesquite, Texas, to Arc Park in Fort Worth was a big adventure.
"That was a pretty big deal," Jennings said. "Fort Worth was a long way. It was an hour drive."
Jennings would go everywhere his dad went with his slow-pitch softball team. He would stay in motels, play video games and watch his dad play first base.
"I remember how fun it was staying in hotels," Jennings said. "The Super 8. For me, Red Roof Inn was the Ritz. My dad was a pretty good left-handed hitter. One of my uncles played on the team. They were pretty good and fun to watch."
This is Father's Day and the Rangers will spend it in San Francisco, where they are playing the Giants. Jennings is a member of their bullpen. He is also a member of a well-known three-generation sports family in the Dallas-Fort Worth area that helped him reach the stature he has achieved in professional sports today.
His late grandfather, James, was a Dallas police officer who worked the Kennedy assassination and was the longtime public address announcer for the Dallas Cowboys, Mesquite Rodeo and other local events.
"He worked the Cowboys until Jerry Jones bought the team," Jennings said. "He didn't want anybody left over from the Tom Landry era so he fired everybody, including my grandfather."
Jennings' father, Jim, played baseball at the University of Texas and in the Rangers' Minor League system.
"He got to [Class] A ball," Jennings said. "He was a quarterback at Dallas Skyline and he dislocated his shoulder. That didn't help. His shoulder just wasn't any good. It just didn't let him do it anymore."
The Rangers' loss was Louise Mandrell's gain. But Jim Jennings did more than work at a beer distributorship and hit softballs over the fence across the state of Texas. He took an active role in his son's development into a three-sport athlete who ultimately became a No. 1 pick of the Colorado Rockies and currently a setup reliever for the Rangers.
"He was always involved," Jennings said. "He was always one of the coaches on my team in baseball and football right from the beginning. My first year was kid pitch. I was eight years old in 1986.
"I didn't pitch much when I was younger. I played catcher and shortstop. I pitched a little bit but I was pretty wild. They tried to get me kicked out the league. I threw hard but I didn't know where it was going. Some mother tried to get me kicked out. I must have hit her kid. My dad didn't teach me how to pitch, but he taught me how to hit. If you look at all the photos when I was a kid, I always had a bat in my hand."
With his father as one of the coaches in the Dallas suburb of Mesquite, Jennings played baseball on the same team year after year.
"We had the same group of coaches and players from age 9-10 all the way until I went to Baylor," Jennings said. "We didn't have any fancy uniforms and we didn't play $1,000 to play. We had T-shirts, iron-on numbers and adjustable hats. We just went out and played.
"In our family, it was sports 24/7. Our family vacations were our regional tournaments in Oklahoma and New Mexico. My sisters probably hated me because we never got to go anywhere fun."
Well, they did go to Arlington Stadium 10-15 times a year to see the Rangers play, often when Nolan Ryan or Charlie Hough were pitching. But when the weather cooled in the fall, Jennings put up his bat and glove until the following spring.
"My dad didn't want me playing baseball year-round," Jennings said. "When it was football season, we were ready for football. He didn't want me playing fall ball. He wouldn't let me. When football season started, I was ready to strap it on. I think playing different sports allowed me to be a better athlete. Football made me tougher. Basketball had different skills. They all helped me as a baseball player."
Jennings ended up as an all-district punter and kicker at Mesquite Poteet High. But baseball was his best sport and he ended up as the 1999 National Player of the Year and Golden Spikes winner at Baylor. He was 13-2 with a 2.58 ERA but he could also hit.
In his last season at Baylor, Jennings hit .382 with 17 home runs and 68 RBIs to earn his second consecutive Big 12 Player of the Year award. He is still the school's all-time leader in slugging percentage.
Louise Mandrell's first baseman taught him well.