Just days after being sworn in as San Francisco’s newest member of the Recreation and Park Commission, longtime City Hall insider Jason Chan quietly resigned rather than face an embarrassing vote at the Board of Supervisors.

Chan, a onetime aide to Mayor Gavin Newsom and former campaign worker for Mayor Ed Lee, also happens to be a housemate of Francis Tsang, the mayor’s commission appointment secretary — who vets candidates for city panels and recommends a winner to Lee.

So maybe it wasn’t surprising that Chan landed the coveted appointment. And since the assignment didn’t require Board of Supervisors confirmation, Supervisor Mark Farrell, standing in last week as acting mayor while Lee was out of the country, promptly swore in Chan during a City Hall ceremony.

Board President London Breed and the majority of her colleagues, however, weren’t given a heads-up and only learned about the swearing-in from a Facebook posting.

They were livid, and they let the mayor’s office know it — particularly since Chan had also neglected to file an economic interest statement with the board clerk as required.

Soon the scramble was on for a vote to undue the appointment, which the board has to right do within 30 days.

Seeing the humiliating fate that awaited him, Chan bowed out — submitting a face-saving resignation letter that said his busy work schedule would keep him from attending Rec and Park meetings for the next few months.

“We get hundreds of emails around issues involving the parks, and we have got to have competent people who understand these issues and can make hard decisions,” Breed said. “I don’t think this (planned rejection vote) was motivated by politics or fighting with the mayor.”

The mayor’s office has been silent — including Tsang. And Chan did not return our call seeking comment.