For a guy who’s played eight minutes in his career, Kris Joseph feels pretty comfortable in an NBA locker room.

Over a crowd of reporters, the second-round pick jokes to Courtney Lee about the wall of questions his veteran Celtics teammate faces after a good night. On his way out, Joseph tells a locker room attendant, “If you want to get me any early Christmas present, stock the fridge with a case of apple juice. I love apple juice.”

In between, Joseph sits alone at his locker, the media walking past him to catch Jeff Green, the other hero in Friday night’s 96-78 blowout of the Blazers. Still, he’s pleased. After all, he just scored his first NBA points — a pair of fourth-quarter free throws in five garbage minutes — on the same day he was recalled from the Red Claws.

“It felt good,” he said. “It was a great game overall. We played hard. We defended well. In turn, we were able to get a large lead and give me the opportunity to get in there in the fourth quarter. It was just a good overall feeling, finally getting in the books — two free throws — guys encouraging me, cheering me on, so it was a great feeling.”

In two games for the C’s NBA Development League affiliate, Joseph averaged 25.5 points, 7.5 rebounds, 3.5 assists, 2.0 steals and 1.9 blocks in 39.0 minutes. Not bad for a couple weeks work.

“The experience in Maine was great,” said Joseph. “It gave me a chance to play, just feel out the NBA-style game, spacing on the court, all types of things. It gave me the opportunity to just be aggressive and play my type of basketball — the type of basketball I’ve been wanting to play for a long time, so I think it was very useful.”

Kris Joseph believes the D-League can only benefit his NBA career. (AP)

Prior to last season, NBA teams could only ship first- and second-year players to their D-League affiliate three times per season. Now, they can send players back and forth as much as they want in the first three years of their career.

So, while Rajon Rondo remains suspended, Joseph will travel with the Celtics to Milwaukee for Saturday’s back-to-back, and the fact he might return to Maine next week doesn’t bother him. The Syracuse product believes the new relationship between the NBA and its minor league of sorts is only “going to be very beneficial” for him.

“Hey, that’s the nature of the business, you know?” he said. “Right now, I’m not in a position where I can just be up here all the time. The coaches and the front office are doing it for the benefit of my future, so I can’t ever go against that. They’re looking out for me, and I think it’s going to turn out to be a great thing.”

Another new wrinkle this season is the fact that the Celtics are now the sole affiliate of the Red Claws. Gone are the Bobcats and 76ers, so Danny Ainge & Co. head the basketball operations and Maine coach Mike Taylor, who spent training camp in Waltham, can maintain continuity for Joseph in the C’s system.

“It’s the same,” said Joseph. “I keep learning the system. Basically, up there, they use me like they use Paul [Pierce] down here. You know what I mean? A lot of the plays are run through me, trying to get me a lot of shots. They just want me to be ultra-aggressive when I’m up there playing, and being that aggressive up there is definitely going to help me for this level as well, playing up here in the NBA.”

Same goes for Joseph’s college teammate and fellow Celtics rookie, first-round pick Fab Melo, who averaged 8.0 points, 2.5 rebounds and 2.5 blocks in his first two games for the Red Claws.

“I got called up,” said Joseph, “and I asked him, did he get called up? And he said, ‘No.’ But he just congratulated me and said to make the most of my opportunity, and I told him — they had a game [Friday] against the L.A. Defenders — so I told him to just go out there and play hard and do what he does.”

The Red Claws suffered the first loss of their season in Joseph’s absence, 97-94 to the Defenders on Friday night, despite eight points, 11 rebounds and two blocks in 29 minutes from Melo. Joseph will likely return to Maine soon, but for the time being he’s pretty comfortable in the NBA, and his Celtics teammates are enjoying the company.

“They’ve been following what I’ve been doing while I was up there,” said Joseph. “They’re really happy for me. They’re proud of me getting some game-time experience, because they know I’ve been working hard while I was down here, so just to see me out here, they’re happy to see me get my first buckets.”

At Joseph’s locker, Celtics strength and conditioning coach Bryan Doo gave the rookie a hard slap on his back. “You’re officially an NBA player now,” he said. If only he had some apple juice to celebrate.