These students have taken the same class

But as he attempts to earn a handful of minutes and a foothold among older players, Green has the distinct advantage of having 20-year-olds Kendrick Perkins and Al Jefferson as teammates. Perkins and Jefferson made the transition from high school to the NBA with varying success. They know the challenges Green will face, on and off the court, in his rookie season. The three have become fast friends.

Before the 18-year-old Green played his first game in a Boston uniform, he joined Perkins and Jefferson for a roundtable discussion about the transition. The players were unfailingly candid on a wide range of subjects, including competition from veteran teammates, snow in New England, and pride in the Southern roots they share. Given the new 19-year-old age limit, it could be the last time an NBA team features three players who bypassed college. If Green, Perkins, and Jefferson develop the way director of basketball operations Danny Ainge expects, part of the NBA past will become the foundation for the Celtics' future.

Kendrick and Al, if you had one piece of advice for Gerald, what would it be?

J efferson: I would say, be smart.

Green: I'll say the best advice they gave me before, both of them, and that was, 'Stay positive.' That can go a long way. If you stay positive on the court, you're going to be good. If you stay positive off the court, you're going to be OK.

Perkins: I ain't going to lie. I've got a rule. I don't let nothing stress me out. Nothing. So, I don't have no worries in my life. I just learned that because that first year was so hard. It was enough stress for me. I was like, 'Man, I can't be killing myself.'

Jefferson: And another thing that stresses you out is family and friends.

Perkins: Right.