Behind the Scenes at D1 Training's Revived Combine Program

They say football is a game of inches, but for dozens of NFL hopefuls each year, their future in the sport comes down to a hundredth of a second.

At D1 Training in Cool Springs, athletes from across the country are working to improve those measurements in the lead-up to the 2026 NFL Draft.

"If you can run a fast 40, they're willing to draft you," says Clif Marshall, D1's senior director of pro athlete training. 

Marshall is referring to the 40-yard dash, one of six drills — alongside the bench press, vertical jump, broad jump, three-cone drill and 20-yard shuttle — an athlete needs to ace at either the NFL Combine or a college pro day to have a shot at making an NFL roster.

As part of D1's revived combine training program, Marshall is coaching more than 20 hand-picked athletes on these exact drills from late January through early March, hoping they can excel during what he and many others call the "underwear Olympics," a reference to the NFL Combine, where athletes complete these drills in front of NFL scouts and executives in, yes, their underclothes. 

"What you've got to look at first and foremost is the NFL Combine is a track meet; it's not a football workout," says Marshall, who previously worked in the NFL combine training industry and as the director of athletic performance at Indiana University before being hired full-time at D1 in September. 

Once the main six drills are completed, players will often be led through position-specific workouts and mental tests, but their draft stock often comes down to those six measurements. But Marshall says there are qualitative signs that someone can make it to the next level. 

"Is he an everyday guy? Can he show up, week six here at D1 Sports, and be just as focused and just as excited as he was on the first day of training? This is a mental and physical grind. I call it an athletic boot camp."

The other thing that stands out, according to Marshall, is their football IQ. They put the athletes through mock interviews and make them draw complex formations and plays on a dry-erase board. 

"The guys that are really good on the board," he continues, "that are really good with the IQ of picking up an offense or a defense, they're going to have a chance to play and stick around, because they're not only great athletes, but they're great football players because of their mindset." 

Among the 20-plus players taking part in the combine program at D1 are a trio of Williamson County Schools alums.

Daniel Rickert and Tim Coutras were teammates at both Nolensville High School and Tennessee Tech, where each earned all-conference honors. Rickert transferred to Virginia for his final collegiate season. There, he compiled 6.5 sacks and 8 tackles for loss to help lead the Cavaliers to arguably their best season in program history.

"We have a lot of pride for where we went to high school," Rickert tells the Williamson Scene. "It'd be an awesome honor [to represent the school in the NFL.]"

During three seasons at TTU, Coutras compiled 11 tackles for loss, 9 interceptions, 15 pass break-ups and four forced fumbles. 

"You always remember where you came from," Coutras says. "To be able to put on for where you played for in high school and grew up as a kid, it's a blessing." 

Summit High School alum Keaten Wade closed out his career with 9 tackles for loss and 2.5 sacks last season at Colorado. It was his second year with the Buffaloes after a pair of campaigns with Kentucky, where he shared a roster with his twin brother Destin, who was the starting quarterback for North Alabama in 2025.

"It's a blessing to be able to train here in WillCo and also just represent your hometown and see how far you can go," Wade added. 

The WCS alums aren't the only local connections among the group in the combine program. Theron Gaines, a teammate of Coutras and Rickert at Tennessee Tech, won two state championships at Oakland. Zaylin Wood played at both MTSU and Vanderbilt. Parker Hughes, from Elizabethtown in East Tennessee, also suited up for the Blue Raiders. UT-Martin's JaMichael McGoy is a Boyd Buchanan alum. 

"I think it says that the Nashville area is loaded with talent," Marshall tells the Williamson Scene. "And then obviously you get into Knoxville, you get into Chattanooga, there's even more talent there. But, there are so many high-level football players in the Nashville area." 

As more talent comes out of the Middle Tennessee area, the D1 Training combine program will only grow. And the higher-profile it gets, D1 has a better chance of landing potential early-round draft picks instead of them going to similar programs in places like Arizona and Florida. The country's top prospects may soon be descending upon Williamson County each year ahead of the NFL Draft.