PITTSBURGH — The crush of attention was expected.

Consider the day that Neil Walker was traded to the Mets, when his wife, Niki, had to shoo reporters away from the front door of the home they had just finished building 20 minutes north of the city.

So yesterday, in what was supposed to be his homecoming, Walker’s pregame duties began with a formal news conference. He conducted it while wearing the Mets’ blue batting- practice jersey.

“I don’t know,” Walker said when asked how he expected to be received. “I certainly have some anxiety toward that situation.”

Rain ensured that he’ll have to wait one more day for the answer, as the weather forced the postponement of Monday night’s Mets-Pirates game. It will be made up as part of a traditional doubleheader beginning at 4:05 p.m. Tuesday.

“He’ll get a huge round of applause — which he should — tonight,” Mets manager Terry Collins said before the rainout. “I hope he gets three hits.”

If it happens, it will come against Jon Niese, the lefthander whom the Mets sent to the Pirates for Walker. He will be opposed by Long Island’s Steven Matz, who hopes to bolster his case for making the All-Star Game.

Though he never stepped to the plate, Walker got what might have been a bit of a sneak preview before Monday night’s game was postponed.

When he took the field to stretch, a row of nine photographers positioned themselves at the dugout, hoping to capture Walker’s first official steps as a visitor in his own home. He obliged them, jogging up the stairs before stepping onto the field.

The gates had yet to open to the public, but that didn’t stop Walker from receiving a warm ovation. Upon spotting his No. 20 jersey, a group of stadium workers at PNC Park stopped their pregame meeting in the stands to serenade Walker with a round of applause.

He acknowledged the cheers, then greeted a few kids in the dugout. It had been months since he had doubled as a ballplayer and an ambassador. But he lapsed right back into the role, the color of his uniform the only thing betraying that he had ever left.

Of course, none of those hometown ties ultimately dissuaded Pirates general manager Neal Huntington from trading Walker to the Mets.

“The fact that Neil was from Pittsburgh was one of the many factors we weighed in our decision process,” Huntington said. “But our end-game focus was to make the decision we believed to be best for the organization.”

With that, a player who for years had been uncommonly bound to his team was cast aside, turned into just a transplant trying to learn the unique rhythms of the big city.

Internally, the Mets had labeled Walker as the closest comparison to a player they knew they would part ways with, Daniel Murphy. But it was the Pirates who floated the idea of swapping Walker for Niese.

From there, the trade came together quickly, setting into motion the events that led to the emotional homecoming.

Walker acknowledged that he has felt slighted by the Pirates. He has expressed disappointment at how his tenure ended. He had been the team’s first-round draft pick and a native son, but he wasn’t deemed worthy of what he considered a legitimate offer at a contract extension.

“Sometimes the business of baseball gets very ugly,” Walker said. “In my case, the end of my time here wasn’t very pretty.”