Now, the brothers and former Auburn teammates are anxiously waiting together to find out where they'll be selected in this weekend's NFL draft.
"It's nerve-racking because you don't know where you're going to go," said David, a cornerback.
"The body's all kind of tensed up," added Kenny, a tailback. "You're predicted to go this pick or that pick and the draft is a big shuffle to me. You never know what to expect. It's just a feeling in your chest that's not going to leave until that Saturday comes and goes, or that Sunday."
Both brothers are hoping that relief comes today, when the first three rounds are held. They'll watch the draft with family and friends at their high school gym in Dacula, Ga.
The Irons brothers have been working out together, along with other NFL hopefuls, in Atlanta. Both played in the Senior Bowl and they even went together for a visit to the New England Patriots.
Close as they are, David is looking forward to a little separation from his brother.
"The journey we had going through Auburn, Little League and high school is probably going to end on Saturday," David said. "No more Dave and Kenny stories.
"I'll get all the attention myself. He was taking all my spotlight at Auburn."
But even he concedes Kenny will likely be the first Irons brother chosen in the draft. The tailback is projected as a second-round pick despite a disappointing, injury-marred senior season.
Kenny battled groin, ankle and toe injuries last season. He still finished with 821 yards and four touchdowns, though those totals marked a major dip from his junior season.
David and Kenny have gone their separate ways before. David started at junior college and Kenny at South Carolina.
Both wound up transferring to Auburn after two years. Kenny said it has been somewhat comforting having his brother go through the same process, comparing notes on what teams ask, and working out together.
NFL officials said they were believed to be the first siblings to be tested at the same time at the combine.
"It makes it easier. You really have no worries," Kenny said. "You don't have to worry about traveling alone. Having your brother makes it just that much easier.
"We just joke around about who's going to go first. It makes it fun."
David's stock appears less certain. He had to field questions about his left knee, on which he's had two operations, and had only a pair of interceptions in two seasons at Auburn.
The second ended Alabama's final drive to preserve a 22-15 victory in the Iron Bowl.
"I feel real good about going the first day," David said. "I feel like I'm a top quality corner. Everybody needs a corner. I feel like I'm in the top five, if not the No. 1 corner out there."
Wherever they fall, Kenny and David will finally get the chance to achieve a dream they shared since childhood.
"I remember way back talking about, â€˜Man, we're going to play in the NFL,'" Kenny said. "But that was like a fantasy. Now it's about to become reality for us. It's just wild."