CHICAGO -- Bulls center Joakim Noah says he made a mistake by trying to enter the Oklahoma City Thunder's locker room after Thursday night's game but downplayed its importance, repeatedly calling Thunder center Kendrick Perkins "an angry dude."

A heated argument occurred after Perkins loudly protested Noah's presence.

Noah had come in to see former teammate Thabo Sefolosha after Sefolosha visited the Bulls' locker room a few minutes before. Words were exchanged between Noah and Perkins before Noah ultimately walked out.

"It doesn't matter," Noah said of the incident. "Just nothing. Just trying to chill with Thabo. It's all good. ... It's not that serious."

"I know that you guys are probably bored right now: We're losing, there's nothing to do, there's nothing else to talk about. But it's not a big deal," Noah said. "Just waking up in the morning having to talk to NBA security. Come on, let's move on. We've got a game tonight. It's not a big deal. No big deal."

Noah said he had no previous history with Perkins. Although there was no physical altercation, the pair continued to exchange words as Noah walked to the Bulls' bus.

"He's just an angry dude, you know?" Noah said. "It's all good."

When asked to clarify his discussion with NBA security, Noah tried to move on.

"We don't have to talk about this anymore," Noah said. "Nothing happened. It's no big deal. I shouldn't have been in that locker room in the first place. Just wanted to say hi to some loved ones, Thabo's family, that's it. It's not a big deal. Perk is an angry dude. It's all good."

Bulls coach Tom Thibodeau knows that former teammates want to see each other after games but seemed surprised Noah went into the Thunder's locker room given that he hasn't played for Oklahoma City.

"You see it sometimes where a player -- like Thabo played for the Bulls," Thibodeau said. "So if a guy played for the team it's not a big deal but usually guys will wait outside."

Thibodeau said this incident would not change the Bulls' policy on allowing former players to enter into their locker room after games.

"If a guy's been with the organization ... that's usually the case," he said. "Usually you have a guy, if he's played [with your team] and he wants to come in and say hello to his old teammates he does. The trainers and people like that. We allow that. It's more or less frowned upon to go into someone else's locker room where you haven't played."

Thibodeau coached Perkins while as an assistant on Doc Rivers' staff with the Boston Celtics. He didn't sound surprised that the emotional big man responded the way he did.

"That's normal," Thibodeau said. "That's usually how teams respond."