ATLANTA — During the summer of 2011, a 25-year-old DeMarre Carroll was two years removed from his professional debut and already on the verge of journeyman status. The Birmingham, Ala. product, who played college ball at Vanderbilt and Missouri before being drafted by the Memphis Grizzlies and then traded to the Houston Rockets, found himself in the Los Angeles neighborhood of Reseda that summer, fighting for his NBA survival.

Carroll arrived at the 360 Health Club in Reseda looking for a proving ground. If he wanted to make an impression, he found the right place: then-Celtics stars Paul Pierce and Kevin Garnett along with All-Stars likes Tyson Chandler and Danny Granger were among the competition. Carroll didn’t have a roster spot, a contract or an All-Star appearance. The Rockets had played him in 11 total minutes before waiving him that April. His young career needed an turnaround.

"I went out there and every pickup game I figured it was a real game to prove and show myself and make myself believe that I could compete with those guys," Carroll said.

Fast forward three years and Carroll’s career prospects are rock solid. On the strength of his versatile defensive ability and an improving offensive game, he’s a bona fide starter at the NBA level. After starting just 22 games in his first four seasons with Memphis, Houston, Denver and Utah, the former first-round pick heard his name called for pregame introductions 73 times last season, his first with the Atlanta Hawks. Carroll responded by averaging career highs with 11.1 points, 5.5 rebounds and a 57.5 true shooting percentage. In turn, he’s become an under-the-radar steal for the Hawks organization, molding himself into one of the league’s celebrated "3-and-D" role players on a team-friendly two-year, $5 million deal.

The defining characteristics of Carroll’s "3-and-D" brethren are simple: wing players that can defend multiple positions, typically shooting guards and small forwards, and space the floor with their 3-point shooting. That sounds simple enough, but Carroll is part of a select group, if not quite on the same level as San Antonio’s Kawhi Leonard and Danny Green or Chicago’s Jimmy Butler.

Carroll’s inclusion is based almost entirely on his dramatically improved jump shot.

From the time he signed with the Hawks as a free agent, he was considered to be a defense-first player, giving the team a wing stopper that could handle point guards and power forwards if needed. Defensive stoppers can be liabilities on the offensive end, though. Hawks coach Mike Budenholzer’s pace-and-space system relies heavily on ball movement and a best-shot-available mentality, and if opposing defenses can sag off certain players then the offensive flow can become disjointed, if not altogether ineffective. Last season’s league-average effective field goal percentage was 50.1; Carroll effectively shot 44.9 percent in his four NBA seasons before arriving in Atlanta.

Former Hawks assistant coach Quin Snyder, who is now the head coach of the Jazz, got to work on his new shooting project. If Carroll, a savvy player with a knack for being in the right spots, was ever going to be a consistent starter in the modern-day NBA he needed to be willing to break his shot down and, essentially, start from scratch.

"He really worked with me a lot on footwork. You know, in my first years when I went to shoot the basketball, I would just shoot it. I really didn’t get myself in the position to shoot. I think we really got down to the nitty-gritty on footwork, catching the ball ready to shoot, coming off picks and squaring my body up," Carroll said. "I think that helped me out a lot. I wasn’t shooting sideways or off-balance shots.

" … Last year was the first time a coach ever really worked with me on footwork and all those types of things. I feel like I’m just cracking the surface. Last year I felt like a rookie, this year I feel like it’s my second year in the league."

At age 27, he enjoyed an excellent "rookie" season. His 3-point percentage jumped from 28.6 to 36.2 while taking more and more outside shots (career-high 41.7 3-point attempt rate). In fact, Carroll’s 97 3-pointers during the 2013-14 season were more than he had made in his previous four NBA seasons and four college seasons combined.

He’s showing signs of even more improvement this season, a contract year: Carroll is shooting a career-high 38.3 percent from distance entering Friday’s game against the Brooklyn Nets.

That outburst coincides with his given role as the go-to defender for the opposing team’s best wing players on a nightly basis. It takes film study — "When I go home, my fiance gets mad at me because I’ve got three TVs in one area … and I’ve got NBA TV on every channel," Carroll said with a laugh. — and a relentless focus on improvement.

"He’s a very, very good fit for us. We’ve gotta be good defensively if we’re going to be the team we want to be, and he kinda gives us that defensive presence, a spirit, if you will. Everybody feeds off of him," Budenholzer said. "Then going to offense, being able to spread the court and make 3s and make shots. It makes out bigs more effective, it makes Jeff (Teague) and our point guards more effective. And he’s growing. He can do more than just catch and shoot a 3. … He can do a little bit of some other things and be another person a team’s gotta account for in pick-and-rolls."

Budenholzer would know the value of a "3-and-D" player.

During his time with the San Antonio Spurs, a tenure that included four NBA titles, Budenholzer watched as the system made use of versatile wings that could defend and shoot from the perimeter, even if they didn’t have a specified nickname at the time. For example, building around twin towers David Robinson and Tim Duncan, the team’s first title came with 6-foot-8 veteran Sean Elliot, a career 37.5 percent 3-point shooter, spreading the defense and posting an above-average 99 defensive rating. Despite an uncharacteristically poor shooting season, Elliot hit 22 of his 55 3-pointers during the Spurs’ 1999 playoff run.

That general blueprint was followed in later championship runs by the likes of Bruce Bowen and Manu Ginobili and, more recently, Green and Leonard.

Budenholzer believes such roles have increased in value over the years, which bodes well for Carroll’s future prospects.

"The game has changed a little bit. My experiences, or my day-to-day, was kind of the end of the run there in San Antonio (seeing) how a guy like Danny Green could grow and Kawhi could grow and are asked to do more things," said Budenholzer, whose team also signed 3-and-D standout Thabo Sefolosha in the offseason. "We ask DeMarre to do more things, a little bit less of the standing around that was probably more prevalent in the NBA. And there’s still some of that. But I think more and more teams are involving more people and using more people and asking people to grow and do more things.

"So I think you’re seeing some guys like DeMarre, the Danny Greens, that are getting a little bit more opportunity. If they put the time and effort in to grow their games, they’re reaping the benefit."

Carroll still remembers the bad times, though, and he’s had his share. His older brother, DeLonte, passed away from a brain tumor. Carroll was 5 years old at the time and carries the memory with him everywhere: tattooed on his left arm, hand-drawn on the court when he’s checking into a game, everywhere. Later on, while in college at Missouri, he was shot in the leg while picking up some teammates from a nightclub. Before the NBA Draft, he was diagnosed with a rare liver disease, a complication that doctors told him would not affect his playing career but may require a transplant after he retires.

All of that came before Reseda, before the struggles to find his niche, when he remembers (and has written about) telling himself, "The NBA is never going to happen."

The 6-foot-8 NBA starter now looks at every step he took as preparation for the next one.

"It was very tough. That’s why now I don’t take anything for granted. I take every opportunity and try to make the most of it. People don’t really understand what I went through, the coaches, all the background," Carroll said of his path to Atlanta. "That Memphis experience really helped me out. Going from Houston to Denver and then to Utah, that really helped me out. I think all my experiences helped me out and made me the man I am today."

He’s come a long way.

And he’s still going.

Now in the final year of his contract, Carroll is well-positioned in the current NBA climate. With the league soon to be raking in the profits from a new TV deal that delivers $2.67 billion annually — approximately half of which is owed to players under the collective bargaining; there’s a projected 67 percent increase in total player salary just from the TV deal alone starting with the 2016-17 season — a versatile two-way player hitting the open market coming off his best season is in excellent position. Of course, the 2016 free agent class will reap the largest benefits, but Carroll is, barring injury, all but guaranteed to have more options this time around: perhaps by signing back-loaded contract to account for when the new TV deal kicks in.

Either way, he’s once again flirting with career numbers and logging 30-plus minutes a night for one of the few winning teams in the Eastern Conference. If DeMarre Carroll was looking to prove something when he arrived at that 360 Health Club that summer, he’s matched at least one goal. Yes, he can compete with those guys.