When Derick Brassard walked into the Rangers’ locker room at the Garden on Wednesday just a few minutes before the pregame warmup, he was comforted by the sight of Rick Nash, his one-time teammate, his one-time linemate, and his one-time ... well, let’s allow the 25-year-old center himself to tell it.

“Rick was my idol when I first got to Columbus after being drafted,” Brassard told The Post following yesterday’s practice. “It was great playing with him there and I’m so happy to be back with him here.

“He sent me a text right after the trade went through to welcome me. Everybody here has been great in making me feel comfortable, and Rick is obviously a big part of that.

“I still look up to him.”

Brassard contributed a goal on a nifty backhand roof job plus three assists including a pair of eye-opening helpers on the backhand in the Rangers’ 6-1 victory over the Penguins, just hours after he and defenseman John Moore arrived from Columbus after having been acquired (with the injured Derek Dorsett) for Marian Gaborik.

“It was great to have a game like that, but I haven’t proven a thing,” Brassard said. “I have to be good every game.”

The next game comes tonight in Pittsburgh against the Penguins — who barely competed on Wednesday, a night after their 15-game winning streak ended in a 4-1 shellacking by the Sabres — in the opener of a three-game trip that also features stops in Carolina tomorrow and in Toronto on Monday.

“I think the trades acted almost like a spark of some sort,” Nash said in reference to the Columbus deal and the one in which the Blueshirts acquired Ryane Clowe from San Jose. “As a group we were prepared for nothing to happen and to go down the playoff stretch with the team we had, but now, it’s like everyone has to prove themselves.