On the day he learned he didn’t make his high school’s varsity team as a freshman, Bryn Forbes came home uncertain if he was tall or athletic enough to seriously pursue basketball.

The doubts flared up again when he didn’t crack his high school’s starting five as a sophomore, when he seldom got off the bench for his AAU team the following summer and when top college programs showed little interest in him by the end of his junior year.

“I could see him questioning himself at times and I’d always say to him, ‘You belong out there,'” said Bryn’s mother, Sue Forbes. “‘You’re supposed to be playing with these guys.’ You have to have somebody in the background who believes in you even when the rest of the world doesn’t. For him, that was usually me.”

A lack of confidence is no longer an issue for Forbes now that he is on the verge of completing an improbable ascent from going overlooked in high school to gaining a foothold in the NBA. After making a surprise push to earn one of the San Antonio Spurs’ final roster spots last season as an undrafted free agent, the late-blooming shooting guard has done all he can to solidify his place with the franchise this month with a sizzling Summer League performance.

Forbes has erupted for back-to-back 35-point games at the Las Vegas Summer League after leading the Utah Summer League in scoring last week at 21.3 points per game. What’s even more encouraging is that Forbes isn’t relying exclusively on his signature 3-point stroke to post those impressive numbers.

In addition to his 41.2 percent shooting from behind the arc, Forbes has displayed creativity off the dribble that wasn’t part of his arsenal in college. The former catch-and-shoot specialist got to the foul line 17 times in a victory over the 76ers on Sunday and has also shown improvement sinking floaters in the lane or finishing through contact at the rim.

A strong Summer League can only help Forbes stake his claim to a roster spot with San Antonio next season. The Spurs already have 12 players signed for next season and two of their three remaining roster spots could be earmarked for free-agent guards Jonathon Simmons and Manu Ginobili depending on if Ginobili postpones retirement another year.

Forbes’ $1.31 million 2017-18 salary won’t become guaranteed until Jan. 10. Spurs general manager R.C. Buford declined to offer assurance that Forbes is part of the franchise’s future plans, but he did acknowledge that the second-year guard has “put himself in a good position” with his steady improvement over the past year.

“From the first day Bryn was in our gym, it was easy to recognize his ability to shoot the ball, but he has invested in himself and bought into the effort of our development program,” Buford said. “He’s a long way from a finished product, but he continues to grow and put himself in a position to gain the confidence of his teammates and coaches.”

Forbes carving out a niche for himself in the NBA is a scenario few could have envisioned when he started high school a decade ago in Lansing, Mich. The slender, baby-faced sharpshooter stood just 5-foot-7 as a freshman and didn’t surpass 6 feet tall until the summer before his senior year.

Point guards can attract interest from Division I programs at that size if they’re quick enough, but Forbes played almost exclusively off ball for Sexton High School as an undersized shooting guard. One of his high school classmates was Iowa-bound point guard Anthony Clemmons. Another was slick-passing future Michigan State All-American Denzel Valentine. As a result, it became Forbes’ role to run off screens and knock down shots that Clemmons and Valentine created for him.

“He had to be a scorer for us,” former Sexton coach Carlton Valentine said. “When you’re a coach, you put guys in places where you can have success. There’s nothing personal about it. You put guys in places where you think they fit. That’s where he fit for us. He could shoot the three. He could shoot it mid-range. He could flat-out score.”

At first, college coaches treated Forbes as an afterthought because they feared he was too small to defend opposing shooting guards at the next level. The Big Ten coaches that pursued Clemmons and Valentine largely still ignored Forbes even after he sprouted to 6-foot-3 and led Sexton to a second straight state championship as a senior, but smaller Division I programs throughout the region began to take notice.

Among those interested was Cleveland State coach Gary Waters, who first became enthralled by Forbes at an Indianapolis AAU tournament the summer before his senior year. Outside shooting was the major selling point of course, but Waters also saw other qualities in Forbes, from his aptitude for the game, to his work ethic, to his relentless motor.

“I said, ‘Man, the young man is more than just a shooter,'” Waters recalled. “If you’re working hard running around screens to get open for shots and people are constantly coming after you, you get tired. And where do you slack on? For most shooters, it’s on defense. But I’m telling you, Bryn had a motor where he never rested on the defensive end. He could go the whole game at the same pace.”

Forbes might have spent his entire college career at Cleveland State were there not family issues pulling him back to Lansing.

It saddened him going weeks at a time without seeing his son Carter, who was born in Lansing about the same time as Forbes started his sophomore year at Cleveland State. He also hated not being able to offer more support for his older sister Erin, who at the time was in the midst of a decade-long battle with Lyme disease.

For those reasons, Forbes explored the possibility of transferring back home to Michigan State. The Spartans only offered Forbes the opportunity to enroll as a preferred walk-on at the end of his high school career, but their interest increased after watching him average 15.6 points per game as a sophomore at Cleveland State while shooting 42.4 percent from behind the arc.

Transferring to Michigan State proved beneficial for Forbes on and off the court.

Forbes thrived as Michigan State’s designated catch-and-shoot specialist, attempting more than twice as many shots behind the arc as inside it. He earned second-team all-Big Ten honors as a senior after sinking 48.1 percent of his threes, averaging 14.4 points per game and teaming with Valentine to lead the Spartans to a 29-win season.

As draft day approached in June 2016, Forbes’ agent informed him that a handful of teams were interested in either selecting him in the second round or signing him as an undrafted free agent. One of those was San Antonio, which did not have a second-round pick but was scrambling to see if it could buy one from another team.

In the end, the Spurs’ inability to find a trade partner didn’t matter. When Forbes went undrafted, he accepted an invitation from the Spurs the next morning.

Said Sue Forbes, “It was a hard night, but it couldn’t have worked out any better.”

Forbes was a long shot to make San Antonio’s roster as a rookie, but the Spurs have valued outside shooting even before it became en vogue in the NBA. They’ve also had success finding and developing lightly regarded players who have taken nontraditional paths to the league.

When Forbes shot 58.8 percent from behind the arc in six preseason games last fall, that was enough for him to edge Livio Jean-Charles, Pato Garino and Ryan Arcidiacono for one of San Antonio’s final roster spots. Head coach Gregg Popovich called him into a room on the eve of cut-down day and informed him, ‘You’re a Spur.”

“It’s a dream I’ve had since I was little to play in this league and to realize my dream with an organization like this makes it that much sweeter,” Forbes tweeted last October. “I can’t describe how thankful I am to all the people who helped me get to this point.”

Forbes spent most of his rookie season adding muscle and working on his ability to create off the dribble while yoyoing between San Antonio and its D-League affiliate in Austin. He averaged 23.3 points per game for Austin, but struggled with his outside shot in limited minutes for the Spurs.

After receiving a surprising 24 minutes for injury-plagued San Antonio in the final game of the Western Conference finals, Forbes returned home to Lansing in late May and immediately turned his attention toward preparing for the Summer League. He knew it was a massive opportunity to prove himself, something he’s had to do at every level since high school.

With every 30-point outburst, Forbes is leaving no doubt. He’s an NBA-caliber player, whether in San Antonio or elsewhere.

“I’m just really happy for him,” Sue Forbes said. “He really feels like he belongs now.”

– – – – – – –

Jeff Eisenberg is the editor of The Dagger on Yahoo Sports. Have a tip? Email him at daggerblog@yahoo.com or follow him on Twitter!

Follow @JeffEisenberg