The straphanger randomly shoved onto tracks by a muttering maniac Saturday is an ER pediatrician who was on his way home from work at the time — and is now just “happy he’s still alive,” his pal told The Post.

The 44-year-old victim was heading back to his Upper West Side pad after a shift at Harlem Hospital and waiting for a No. 1 train at the 50th Street and Seventh Avenue station in Manhattan around 7:50 p.m. when the nut came up behind him, according to cops and the friend, Takayuki Matsumoto.

“[The unhinged attacker] was screaming and walking toward him, and the next thing, [the victim] was pushed,” said Matsumoto, speaking to The Post at the home of the injured rider, who was inside sleeping while recovering, on Sunday.

“It’s not like he was walking on the edge of the platform or anything,” the man said of his doctor friend. “He was walking in the middle of it, and suddenly, this guy approached him and pushed him.

“His staff at the hospital said, ‘Don’t take the train anymore,’ ” Matsumoto added of his pal.

“He’s lucky he’s OK. He’s happy that he’s still alive.”

Matsumoto, 62, said the victim was aware at the time that there was a train coming into the station in under 4 minutes, so he scrambled back onto the platform quickly with help from “a nice couple and a lady.”

The doctor, whose name is being withheld by The Post, suffered bruises to his face and leg.

Cops are currently searching for the suspect, who was described as around 6 feet tall and wearing a white shirt, black shorts and a black backpack.

The attack was one of a slew of recent violent incidents on the rails.

Police also are looking for the man who stabbed another subway rider in the neck during a dispute at an East Village subway station Saturday night.

In addition, a masked stranger slashed a 29-year-old woman on a Lower Manhattan train late Wednesday when she refused to hand him her bag — and he is still in the wind, too.

The ER doc’s pal said Saturday’s attack on his buddy will unfortunately do little to deter the victim from riding the subway.

“That’s the only way he can get to the hospital,” the friend said.

Meanwhile all the violence did not stop clueless MTA officials crowing Sunday that July marked the lowest subway violence month since 1995.

But despite the transit agency’s renewed assurances, subway violence has continued to terrorize straphangers.

The Post reported in May that felony assaults were up 19% since the start of the year compared to the same period last year.

Out of the 255 assaults at that point this year, 93 — or 36% — were on city police officers and MTA workers, compared to just 44 such attacks over the same span in 2019.

In June, aspiring Thai model Zina Raksasulee, 26, was viciously beaten and robbed at a Brooklyn subway station, too.

Her alleged attacker, 54-year-old ex-con Lewis Doctor, had been released on bail after an earlier arrest.

On May 14, Sherlock Arana, a 37-year-old vagrant with 20 busts on his rap sheet, also shoved a 70-year-old grandma visiting from Los Angeles against the wall of a Midtown subway station.

One month earlier, a 46-year-old maniac with a troubling history of mental health issues — including an attack on a 13-year-old boy — slashed a woman in the neck at a SoHo subway station.

And in January, a deranged homeless man shoved an innocent woman into a moving Manhattan subway train at the 18th Street station in an unprovoked attack.

According to prosecutors, Markeese Brazelis, 26, told cops he allegedly attacked the woman simply “because I wanted to.”