The mood in the Celtics  locker room was light. Extremely light. A bunch of the players were eager to leave and get some food together, but Ray Allen  stayed behind to answer every last one of the reporters’ questions.
He sounded like a future NBA coach, discussing everything from rivalries to winning streaks to what today’s young players are lacking. Here’s what Allen, who scored 18 points on 7-of-13 shooting, had to say after the Celtics’ 12th consecutive victory, a 102-90 win over the Hawks …
If the Knicks aren’t your rival, then who is?
(Waiting, waiting, waiting …) “I don’t really look at a Western Conference team, because we don’t play them enough. The playoff teams we’ve played are definitely rivals. In the Eastern Conference, we talked about Detroit … but they’re done. Cleveland’s now done. Orlando right now is the team that we’d have to say is our rivals.
“To me, it’s all based on playoffs. The regular season gets you warmed up for it, because you know you’re going to see them. You want to leave something for them to think about.”
How have the Big Three avoided the injury bug?
(Knocking on wood) “With me, Paul [Pierce] and Kevin [Garnett], it’s not about the prestige of the job, it’s about the game itself. It’s about playing basketball and doing whatever you need to do to stay heatlhy and take care of our bodies.
“That’s one thing between the three of us — whether we’re in the weight room or getting up shots — we’re going to do whatever we need to do to help this team.”
Are you surprised by Semih Erden’s success so far this season?
“I’m not surprised at all. He’s got great promise. He’s very talented. I think we all forget that he’s a rookie. We expect a lot from him in that position, and it’s only going to make him better in the long run. …
“I played with a lot of young big men who were just doomed, because they had nobody to offer tutelage, that had been through it and had done some good things in the league. For him to come here is probably one of the biggest blessings he could ever ask for. He probably doesn’t realize it now, but 6-7 years down the road he’s going to realize how special it was for him.”
How important are the veterans to Erden’s success?
“Whether they’re on the business side or player development, I don’t see enough past players on rosters. There’s too many young guys in the league nowadays who need the expertise on how to play this game — not just putting the ball in the whole but understanding how to be a teammate, be a professional, be that guy who knows how to take a hard foul. We don’t have those guys anymore.”
How was the offense different with Nate Robinson  running the show?
“Offensively, we didn’t have a great rhythm early in the game. Even a week ago, when [Rajon] Rondo was out, it was different, because Shaq was out there and he gave us a better rhythm with Nate out there.
“[Thursday], it was different. We had to figure it out all over again with Nate and Semih out there. It took a while. About the third or fourth quarter, we established a rhythm offensively and then we locked down.”
Are you impressed by the team’s 12-game winning streak?
“Not really. If I had to guess who we beat these past 12 games, I couldn’t tell you. It’s behind me. I don’t have to worry about those teams we played.
“When you lose a game, that always haunts you. When you watch the highlights on SportsCenter, it kinda jabs you in the side knowing you lost to them the last time you played.”
Why do you think the team has had more success against the so-called “athletic” teams this season?
“A lot of that is Kevin being a little bit healthier, just having his legs underneath him. I don’t know what he’s averaging rebound-wise, but he’s bringing them down and he’s keeping those other guys off the glass. … It does make a difference when you keep those young guys off the glass.”
Even with a 21-4 record, can the Celtics still improve?
“I think we can work on everything. There’s not one thing we can’t improve on.”