TORONTO -- A couple of minutes into Game 3 of Toronto's opening-round playoff series against Washington, OG Anunoby took an elbow to the back from eight-year NBA veteran Markieff Morris.

The Raptors rookie put two hands to Morris's chest and shoved him back. A scuffle ensued.

The bright lights of the post-season can prove too much for a first-timer -- think Terrence Ross in the Raptors' playoff series against Brooklyn in 2014.

But through the first six playoff games of his brief NBA career, Anunoby has stood up to the challenge, knocking down shots with an icy sureness, and coming up huge on the defensive end against Washington's all-stars John Wall and Bradley Beal.

Raptors coach Dwane Casey calls Anunoby an "old-head rookie."

"He's very confident in who he is and what he is and his role," Casey said. "I think that's a lot of the maturity factor that you see is the confidence he has in himself, which is a good thing. I haven't seen it shaken yet, so hopefully it continues and continues to grow. I think this year has been great for the young man. He's done everything we've asked him to, he's grown in so many areas. This is only the beginning for him."

The Raptors felt they got the steal of last year's NBA draft when Anunoby dropped to 23rd overall after missing most of his final season at Indiana with a torn ACL.

His rehabilitation was swift, and by the 13th game of the season he'd played his way into the starting lineup.

He's a 47 per cent shooter, averaging 5.9 points in 20 minutes a game in the regular-season. Incredibly, his stats have improved in the post-season -- he's shooting a sizzling 59 per cent and 47 per cent from the three-point line.

The 20-year-old Anunoby is about to face the toughest test of his career in stopping LeBron James.

Bring it, the rookie says.

"I'm pretty confident," he said. "I think each time I've played him it's gotten better guarding him, so, I'm confident.

"He's pretty strong but I feel like I'm strong too."

Anunoby, whose full name is Ogugua and who wears Ugg slippers when he's not in sneakers, is a bit of an enigma. Quiet but not impolite, he wastes few words when answering questions from reporters.

The media probed the six-foot-eight small forward on Monday with numerous questions about James. Asked if the gameplan was to allow nothing easy for the Cavs superstar, he responded with "Yeah."

Can you tire him out?

"You have to ask him. I don't know if he's tired. I'm going to try to get him tired."

Do you get nervous before big games?

"No. I have no reason to be nervous."

Anunoby's poise in the post-season has come as no surprise to DeMar DeRozan, who said that's part of his personality.

"He's a unique individual," DeRozan said with a laugh, recently. "If you know him, he's a unique individual. And I'll leave it at that. So it's not surprising at all.

"No, I'm not going to expand on that," DeRozan grinned. "Maybe one day it'll come out. I'm not going to share it today. OG is a special individual. I love him."

While the Cavs' scoring versus Toronto was at its lowest with Anunoby guarding James, the responsibility for stopping the Cavs superstar won't fall solely on the rookie's shoulders, Casey said.

"It's the Toronto Raptors versus LeBron James, it's not gonna be a one-on-one matchup, LeBron James versus OG," Casey said. "You're not gonna stop him one-on-one. He's got four other teammates that's gotta help him.

"He's gotta do his job on the ball, the weak side has to do their job on the ball, because there's certain things we wanna do, certain places we need to be, and if they're not, it's all for nought."