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LAS VEGAS — For most NBA fans, summer league is an opportunity for a first look at the incoming rookie class. For a few veteran journeymen, it's an opportunity for a second chance at finding a home in the league.

The rosters at the NBA's annual tournament-turned-industry convention skew young. The top picks, the Zion Williamsons and RJ Barretts, are the headliners, but the rosters are mostly filled by undrafted players, G Leaguers and fringe prospects just fighting to get noticed by NBA general managers and maybe score a camp invite or two-way contract.

Peppered into the summer-league rosters, though, are a handful of veterans. Names you might actually remember from the NBA of years past. They washed out of the league for whatever reason. Maybe they were injured, maybe they had the wrong attitude. They're here, too, battling for one of the last few roster spots with players a half-decade or more younger than they are.

"I look at summer league as a time to get better," says forward Thomas Robinson, a former University of Kansas star and the No. 5 overall pick in the 2012 NBA draft who played for six teams in five seasons in the league. "It's an opportunity to showcase yourself for all 30 teams. That's what I wanted to do. I've been gone for a while, so I wanted to show teams that I'm back, I'm healthy, I'm a lot smarter player, I'm a better player."

The 28-year-old Robinson is playing for the San Antonio Spurs' summer-league team in Las Vegas as he looks to put himself back on teams' radars. He last played in the NBA with the Los Angeles Lakers in 2016-17 and then signed a deal with a Russian team the following summer when NBA interest dried up. The Atlanta Hawks invited him to training camp last fall but cut him before the season began. He played the 2018-19 season for the Beikong Fly Dragons of the Chinese Basketball Association before signing with the Boston Celtics' G League affiliate, the Maine Red Claws.

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Joining Robinson on the summer Spurs is point guard Darius Morris, a 2011 second-round pick of the Lakers whose four seasons in the NBA also included stops with the Philadelphia 76ers, Los Angeles Clippers, Memphis Grizzlies and Brooklyn Nets. He's been out of the league since 2015, playing briefly in China but sticking mostly in the G League. Morris played in summer league early on in his career when he was in the same position as the kids that make up most of his teammates. Back then, he may have looked a little bit funny at someone his age still playing at summer league, trying to take his spot.

"When you're a young guy, you're a little on edge about it because you're uncertain about your own future," Morris says. "But once you see, this old guy is cool, he's helping me out, he's talking to me, he's communicating with me, they kind of let their guard down."

Morris' NBA career ground to a halt in the summer of 2015 when he suffered a broken foot that kept him out most of the 2015-16 season. By the time he was healthy, there just wasn't a spot for him on an NBA roster.

It isn't always injuries that lead to talented players being squeezed out. Only 450 roster spots are available, plus 60 two-way spots, and players on the fringes often find themselves on the outside, forced to consider other options. Jeff Withey, Robinson's former college teammate at Kansas, simply decided after parts of five NBA seasons that the opportunities available to him in Turkey and Greece were more stable.

"I could have gone the route of going to training camp and trying to make a team," says Withey, who is playing in Vegas with the Washington Wizards. "But it's hard to turn down guaranteed money overseas. So it's one of those things where, do you want to have a role and guaranteed money or do you want to grind to just get on a roster by going to training camp? So we went that way."

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For Robinson, it was a harsh but necessary conversation with a general manager that made him realize the NBA may not work out for him unless he seriously changed his approach. Growing up, Robinson was one of those freak athletes who never had to learn the fundamentals of basketball because he could get by on physical tools alone. Pure talent made him a five-star college recruit and, later, a lottery pick of the Sacramento Kings.

But Robinson's NBA career never took off. He bounced around the league, with short-lived stints in Sacramento, Houston, Portland, Philadelphia, Brooklyn and L.A. Each of those teams believed they could be the one to finally unlock a talent that was once seen as a future star. Each of them discovered the same thing: Robinson didn't understand the game, and he had a tendency to mentally check out when his minutes were cut.

Finally, one GM sat him down and told him, straight-up, "You have no basketball IQ, and that's why you won't stick in the league."

Those were tough words for a former top-five pick to hear, but it proved to be exactly the reality check he needed.

"It's hard when you tell somebody to work on their IQ," Robinson says now. "Because how do you do that? It's terminology and knowing the right places to be and just watching the game. You have to know the game. I've been a raw talent all my life, so I got this far by not having to know certain things or do certain things. That's been the case with me.

"Over the course of the last two years, I really locked in on watching certain players. I changed my game from watching Kobe and LeBron to paying attention to Draymond and Montrezl Harrell, and how they're finding success in the league. That's helped make the game so much easier for me."

As Robinson attempts to show NBA GMs that he deserves a second chance, summer league is about more than just auditioning himself as a player. He wants teams to know that if they bring him in, the personal growth and attitude shift he underwent in the past two years will make him a positive veteran influence for their locker room. Maybe he can help a young player avoid becoming the next Thomas Robinson.

"Even without being a major-minute guy in the league, I still have experience," he says. "Part of being a veteran is you're mature, you know more than everybody. So I have to show that. I can't keep it to myself. I can't watch a young guy messing up and not tell him what to do to not end up like how I was."

Getting on the floor at summer league can be a struggle if you're not a current draft pick the organization has a vested interest in developing. Morris played well in the Spurs' opening game at the Salt Lake City Summer League on July 1 but has mostly been out of the rotation since then, both in Utah and in Vegas. If the goal is to use summer league as an avenue back into the NBA, selling himself as a veteran leader could be his only option. Playing in Vegas as an elder statesman is just another box to check on a career that's run the full spectrum of NBA experiences.

"I think I'm in that in-between stage of my career where I can offer a lot of advice," Morris says. "I've started in the playoffs, I've started in the regular season, I've played with legends, I've been cut before, I've been in the G League, I've signed 10-days, I've played side by side with Kobe. I can relate to anybody. If you've got a young star that's going back and forth in the G League, I know all that advice. But I'm still entering my prime and I can play at a high level. I have a lot left."

Robinson and Morris are both 28 years old. Withey is 29. All three are still in their physical primes, clearly capable of contributing in different ways. But competition for roster spots is stiff. Many teams would rather bring in someone younger, with more upside and less baggage, than take a chance on a journeyman approaching 30 who's bounced around for a half-decade or more.

"You definitely do be having those doubts, especially as you get a little bit older and things don't happen overnight," Morris says. "I'm human, so I definitely get those thoughts. That's when I let my faith in God take over. The fact that teams keep calling lets you know that you're still on their radar. When they stop calling, that's when I'll start thinking maybe it's over. It's just trying to find the right fit and staying in front of them. A lot of stuff is just about timing. Since I've been out, I've been in the wrong place at the wrong time. Now it's about being in the right place at the right time."

Withey says his agent has received feelers from a few teams with varying levels of interest. He's open to returning to Europe if an NBA opportunity doesn't materialize, or possibly getting into coaching. Robinson isn't ready to give up yet, even if that means spending another year in the G League. He's fought too hard for this opportunity to make good on what was once a promising career.

"I'm not 30, man," Robinson says. "I'm only 28. I'm not no old, retired player. I can still play. I can jump just as high as these young guys. I can run just as fast. I can play with anybody. I'm just trying to get back and show teams that I'm ready to return."

Final roster decisions won't come until October. There are still free-agent minicamps and private workouts throughout the summer. But for these journeymen, summer league is a lifeline, a foot back into the door of the NBA.

"I'm pretty optimistic about it," Withey says. "But even if nothing comes about, I played in the NBA for five years and I got my pension, so I'm good."

Sean Highkin covers the NBA for Bleacher Report. He is currently based in Portland. Follow him on Twitter at @highkin.