"Oh my God, people are going to die," gasped Kyle Scott, a writer for the Philadelphia sports blog Crossing Broad.
The event - organized by photographers from the New Orleans Times-Picayune - was soon canceled.
"I admit this was a bad idea," Michael DeMocker, one of the photographers involved, wrote in a tweet Friday afternoon.
The newspaper "intended to build camaraderie" with the event, an editor wrote Friday on the newspaper's website, NOLA.com. "Instead, the proposed event touched off controversy among Eagles fans."
It's unclear what, if anything, would have happened had the event continued as planned. Still, police said they were prepared to curb any rowdiness at the game, with plainclothes and uniformed officers stationed throughout Lincoln Financial Field.
The stadium's private security detail will also be on hand to catch troublemakers, with some dressed in Saints garb - a common practice - Philadelphia Police Chief Inspector Joe Sullivan said Friday.
"It results in numerous ejections of people who feel that they can intimidate or confront someone," Sullivan said.
Philadelphia plainclothes officers will also be dressed like fans, Sullivan said, but without jerseys, and with identification "readily available."
The department works with event staff to determine "problem areas" in the stadium - essentially, where fans have demonstrated rowdy behavior - to curb bad behavior, he said.
Earlier this season, a Center City business owner made allegations that a group of Eagles fans had beaten him unconscious outside the stadium after a Detroit Lions game because he was wearing Lions gear.
Sullivan said he expected Saturday's game to proceed smoothly and stressed that the department has a zero-tolerance policy on bad behavior inside and outside the stadium.
He advised fans to arrive at stadium gates early, as "people will be wearing multiple layers of clothing, and that slows up the screening process."
The department is also hoping the cold weather will deter would-be rabble-rousers.
"The majority of people coming to the stadium are going to be very focused on the game and not have any interest in causing any trouble whatsoever," Sullivan said. "But any time you have 70,000 people in one place, you're always going to have a few people that just have to behave poorly."