The two began moving up the ranks together while playing pee-wee and bantam level hockey in the Barrie Colts system eight years ago.
They were ultimately chosen by Owen Sound in consecutive rounds of the Ontario Hockey League's 2011 priority selection draft and, most recently, were rated back-to-back on NHL Central Scouting's final ranking of the top draft-eligible North American skaters.
Nastasiuk, a 6-foot-1.25, 190-pound right wing, is No. 13 on NHL Central Scouting's final ranking of the top draft-eligible North American skaters. The second-highest-rated North American right wing and native of Barrie, Ont., had 20 goals, 20 assists in 62 regular-season games for Owen Sound in 2012-13. He chipped in with four goals and seven assists in 12 playoff games.
"Everywhere we go, it seems like you can't separate us," Nastasiuk told NHL.com. "We're on the same winter team, same summer team and now we're on the same OHL team. It's pretty special to go through all this with him."
Bigras, a 6-0.5, 211-pound defenseman, is No. 14 on Central's final ranking release -- the sixth highest-ranked defender. The native of Elmvale, Ont., had eight goals, 30 assists and a plus-35 rating in 68 regular-season games.
"It's neat … I grew up with him my whole life, so it's good to see him doing so well," Bigras told NHL.com. "I think just going through this, together, we were able to help each other out and push each other."
Nastasiuk was asked who he felt would be selected first among Attack teammates in the 2013 NHL Draft at Prudential Center in Newark, N.J.
"It really doesn't matter, but it'll probably be him," Nastasiuk said with a grin. "But no matter what happens and whenever he goes, I'll be thrilled to hear his name called."
The only time they've been matched against each other in eight years was last January at the Home Hardware Top Prospects Game in Halifax, Nova Scotia.
Nastasiuk and Bigras were roommates during their six-day stay at the 2013 NHL Scouting Combine at the Westin Bristol Place in Toronto. The odds of them being drafted by the same team are slim unless the Columbus Blue Jackets, Calgary Flames, Buffalo Sabres or Dallas Stars, who each have multiple picks in the first round, make it happen.
"He does something to contribute to a win every shift," Central Scouting's Chris Edwards said of Nastasiuk. "He's an excellent penalty killer and uses his long reach very well, is smart in his ability to be in the right place. Earlier in the year, I would have called him a puck chaser, but he played with purpose and made a big jump over the second half of the season. I think he could end up becoming a big pro."
Nastasiuk was ranked No. 33 on Central's midterm report in January.
"I feel just playing and getting time on the ice really helped my growth as a player," Nastasiuk said. "I had a good talk with the coaches just after the Christmas break, and my confidence grew. They were giving me chances and that helped my confidence. I love being the underdog and in pressure moments."
Both Nastasiuk and Bigras suited up for gold medal-winning Canada at the World Under-18 Championship in Sochi, Russia. In seven tournament games, Nastasiuk had two goals, four points and a plus-4 rating and Bigras finished with three assists and a plus-8 rating.
"Chris [Bigras] will never bring you out of your seat with fancy goals, but he doesn't make many mistakes either and keeps it simple," Edwards said. "He moves the puck well and every time he gets it, he makes a good play or outlet pass and gets it up the ice. He has that ability to skate the puck up ice and create offensive chances."
In addition to earning a gold medal at the U-18 World Championship in April, Bigras also won gold with Canada at the 2012 Memorial of Ivan Hlinka.
He was asked his thoughts on the most important factors to becoming an NHL defenseman today.
"Nowadays, you need hockey smarts and also your speed and footwork need to be there," Bigras said. "The game is so fast and the forwards move the puck so quick, that you have to be able to think quickly and move quickly."
Central Scouting's David Gregory explained that both players really captured the eye of scouts over the second half of the season. Bigras advanced five rungs on the final ranking of North American skaters from No. 19 at the midterm report.
"One of the things we track is progression and how players begin to handle extra ice time, more important situations and the response to the fact that now they're being keyed on because they developed into an important player," Gregory told NHL.com. "Both of these guys responded to those things really well.
"They are skilled and talented, and their compete level and understanding of the game took both of them to that next level in the league."