Great things often grow from humble beginnings.

The same can be said of some of the Toronto Raptors' most significant contributors during this historic run to the NBA Finals. The Raptors 905, the team's G League franchise, has been Toronto's ace in the hole when it comes to helping grow late draft picks into playoff performers.

Norman Powell was selected 46th overall in the 2015 NBA draft, a spot where the majority of selected players rarely enjoy long-term NBA careers. Toronto drafted Pascal Siakam with the No. 27 pick in 2016, though like Powell he was ranked in the mid-40s by many analysts. Fred VanVleet went undrafted in 2016 before the Raptors signed him to a training camp deal.

Players with such low expectations upon entering the league rarely make meaningful contributions. Yet all three have been crucial to Toronto's title shot.

Both Raptors guard Fred VanVleet, left, and head coach Nick Nurse, right, spent time in the G League. (Gregory Shamus/Getty Images)

"Those [three] are people that are now part of a system and are ingrained in what is now Raptors' culture," said Jama Mahlalela, the 905's head coach. "For them, it began early in their careers with the 905. It helped to really formulate who they are as Raptors now."

After being drafted by the Raptors, all three of Powell, Siakam, and VanVleet spent time with Toronto's development affiliate.

Based in Mississauga, Ont., the 905 have enjoyed success since its inaugural season in 2015, winning the championships in 2017 and advancing to the league final in 2018.

"[The G League is] a chance to develop your game and gain confidence," said Chad Sanders, the 905's general manager. "It's better than sitting toward the end of the bench and not getting a constant role, constant time on the court. This allows the team to go right up the stream. We run the same offence, the same schemes [as the Raptors]. It gives them a chance to go out there and play with a team and stay fresh and stay ready and develop."

In 2015-16, Powell averaged 24.9 points in his eight games in the G League. When the 905 won the championship the following season, Siakam was named MVP of the final. He put up numbers similar to his numbers so far during this NBA playoff run — averaging 18.0 points, 7.9 rebounds and 2.4 assists per game. Not to be outdone, VanVleet averaged 22.0 points, 6.0 rebounds and 11.5 assists in that same championship series.

"Those players can be put in big situations, and yes, the G League playoffs are not the same as the NBA playoffs," Mahlalela said. "But there's pressure, there's responsibility, there's coverages, there's understanding what's on the floor.

"Them getting reps there as a sort of a nice practice ground, it's served them well. Fred returned to glory finding his shot again. It comes from experience. It comes from doing it more times than other people have. He's had games where he's made big shots. [The 905] is a good example of that for him."

"We talk about the playoffs, and their experiences they had with the 905," Sanders said. "They've been to the playoffs, winning a G League championship. And now just a couple years later, a chance to try to repeat that at this new level is really incredible."

The story doesn't end with Powell, Siakam, and VanVleet. The 905 continues to pump talent into the NBA. This year, Canadian Chris Boucher became the first player in history to win the G League MVP and defensive player of the year in the same year. Malcolm Miller is a sweet-shooting wing who has been with the 905 for two seasons. Both were signed to the Raptors roster before the playoff run.

A year ago, Alfonzo McKinnie, left, was playing for the Raptors 905. Now he's playing against the big club as a member of the Golden State Warriors in the NBA Finals. (Associated Press)

"There's a clear line that's drawn between the 905 team and the Raptors team," Mahlalela said. "Fred and Pascal and Delon [Wright] and Norm were the early guys, the first guys to walk that line. But now this next generation is coming through. They've seen the path. They're on the same path. They can get there in a year or two from now. It can be the exact same process. "

"For both of those guys [Boucher and Miller] I think the opportunity's there," Sanders said.

The G League connections extend yet further. Toronto's Danny Green played in what was then the D-League in 2010-11. On the other side of the court, Alfonzo McKinnie has become a key contributor for the Warriors after spending last season as an affiliate player starting for the Raptors 905. Toronto head coach Nick Nurse won G League championships coaching the Iowa Energy in 2011 and the Rio Grande Valley Vipers in 2013.

However, the three of Powell, Siakam, and VanVleet are the crown jewels of the 905 system. If the Raptors are going to beat the Warriors, Powell, Siakam, and VanVleet will need to duplicate their dominant performances of yesteryear with the Raptors 905.