From the sideline of a pro day, an NFL executive was unenthused by 40 times and more eager to peek at something else.

"I'm looking for late-bloomers," the exec said.

He explained that players might have a 10-year window of peak performance. He's looking for players who haven't started theirs yet: guys who weren't stars in college, whose skills are still developing because of their youth or whose minimal tread provides a clean injury outlook.

Not every scout takes this linear approach, but most agree that finding players who will last is crucial in today's age-centric game, and a seven-round draft format leaves room for risk-taking.

LSU's Arden Key could develop into a player who gets double-digit sacks at the next level. Gerald Herbert/AP, File

The days of holding on to players well into their 30s for sentiment are gone. Just ask Pete Carroll, whose Seattle Seahawks moved on from 30-year-old Richard Sherman after the All-Pro corner suffered a torn Achilles.

"You become so connected to the players you've been with for a while -- how long can you stay clear-thinking about their status and how they are performing?" Carroll said. "It is a challenge. You have to figure it out every year. Every guy is a unique individual story."

With star players getting cut each March, teams must restock with youthful playmakers they hope will merit a lucrative second contract.

After speaking with several NFL scouts and combine prospects, here's a list of unfinished products who might fit the "late bloomers" criteria:

OLB Arden Key

6-foot-6, 238 pounds

Why a late bloomer: Teams considering drafting Key hope he maximizes his sizable potential after maturity issues at LSU. He took a leave of absence from LSU in February 2017 for undisclosed reasons. Key, who turns 22 in May, has been honest during the interview process, telling teams he's been sober for more than a year. He has reasonable wear and tear after 31 college games. Pass-rush coach Chuck Smith said Key has elite bendability off the edge. "He's challenging for 10 sacks Day 1," Smith said.

Scout's take: "The kid was being honest. He's not a dumb kid. He's just going to need some time."

TE Dallas Goedert

6-5, 256

Why a late bloomer: Goedert intrigues teams with his pass-catching ability but has room for growth coming out of South Dakota State. He was not heavily recruited out of high school and once considered himself undersized. No longer.

Goedert's take: "I came out of high school at 200 pounds. We didn't have a weight-room program there, so I was able to get quite a bit stronger throughout college. It's a big benefit that I'm not a finished product."

LB Tremaine Edmunds

6-5, 250

Why a late bloomer: Combination of youth and athleticism has teams believing they can mold him into something special. Edmunds will be 19 when drafted (he turns 20 on May 2). A two-year starter for Virginia Tech without major injury concerns, he probably is a Day 1 selection.

Scout's take: "All upside with him. The athletic talent is so great that you don't always see that put together on film. Maybe it's a little bit of being a young guy, a three-year guy, growing into his body still. ... He truly was a 19-year-old playing in the ACC. You hope with more coaching, he can take another step or two."

OT Joseph Noteboom

6-5, 309

Why a late bloomer: Raw skill set out of high school due in part to 270-pound frame. A three-star recruit, he redshirted his first year at TCU but started three seasons and has slowly developed into a Day 2 prospect.

Noteboom's take: "You want to draft a guy you can play with down the road. If a guy has already peaked, then you know what you're getting rather than guys around the same level who can be really good down the line. I'm on the level to peak. I can get stronger, bigger, learn the game more."

QB/RB Quinton Flowers

5-10, 210

Why a late bloomer: Projects more as a running back in the NFL. Flowers didn't take much between-the-tackles pounding while starting three seasons at quarterback for USF, though he did run the ball 588 times for the Bulls. He's considered a Day 3 prospect or undrafted free agent who can develop behind the scenes.

Scout's take: "Not a quarterback, but he's a tough guy when he runs and you feel his power. Rocked-up, muscle-tough guy. Good guy to have on your team."

OT Kolton Miller: He started one full season at UCLA, which is not ideal from a body-of-work standpoint, but since his 2016 injuries are not considered long-term issues, he should be fresh and ready for a long career.

LB Darius Leonard: He couldn't get a Power 5 scholarship offer out of high school, but after four impressive seasons at South Carolina State, the NFL definitely wants him.