The crowd of more than 100 chanted "We want Brett," and carried signs reading, "Favre for President" or "Favre Forever." Many in the parking lot wore No. 4 jerseys, tossed footballs and grilled.
"We've always appreciated the passion of our fans," the Packers said in a statement. Team spokesman Jeff Blumb said there would be no other comment.
The rally in Green Bay, Wis., was the brainchild of brothers Adam and Erick Rolfson, who on Friday tried to think of a way to keep Favre in Green Bay. Another rally is planned for Monday night in suburban Milwaukee and every Sunday thereafter at Lambeau Field until Favre is back.
The brothers also are demanding an emergency meeting of stockholders "to help control the fate of our quarterback," Erick Rolfson said.
A message left for Favre's agent, James "Bus" Cook, wasn't immediately returned Sunday.
Favre retired March 6 after 16 seasons with the team. He changed his mind and asked for his release because it appeared the Packers were not receptive to having him play again.
On Saturday, general manager Ted Thompson and coach Mike McCarthy said they didn't plan to grant Favre's request. And while Thompson said Favre could rejoin the team in a "different role," the Packers were committed to going with Aaron Rodgers as their starter.
Speaking later to ESPN.com's John Clayton, Thompson said he is prepared to accept Favre's return and not necessarily as a backup.
"It's not accurate," Thompson said of the AP report that Favre would come back as a backup. "We don't know what role that would be. He can come back as an active member of the Green Bay Packers."
Thompson reaffirmed to ESPN that the Packers won't release Favre. He would not discuss trading the future Hall of Fame quarterback. Thompson said he had not received any inquiries from other teams as of Saturday morning.
"I don't want to deal in hypotheticals," Thompson said. "Brett is still retired. I know that there has been a lot of publicity about him being released, but if he applies for reinstatement, he will go back on the Green Bay Packers' active roster and we will deal with it then."
Rodgers, who is playing in the American Century Celebrity Golf Championship in Lake Tahoe, Calif., is trying to block out the Favre talk.
"It's always difficult when your name is in the media all the time and there's a lot of speculation about different things," Rodgers said.
"I'm just trying to enjoy the weekend I'm just focused on that, on working out and going back to Green Bay next week for training camp."
"We wanted to create a forum for fans' voices to be heard," Adam Rolfson, 36, told The Associated Press by phone. "I don't understand how you deny somebody that threw for 4,000 yards [last season] a starting position. I can think of at least 25 teams in the NFL that would jump at the opportunity to have Brett Favre be their starting quarterback."
The brothers had hoped Sunday's rally, only a day in the making, would have attracted more people.
Packers fans are divided on the 38-year-old quarterback. While Favre clearly has his supporters, others seem weary of another offseason of retirement-related drama.
In an unscientific poll on the Milwaukee Journal Sentinel's Web site, 47.2 percent of fans said they wanted Favre to play for the Packers next season and 46.5 percent said he should "retire already." Only 6.3 percent of the 17,000-plus fans who voted in the poll as of Sunday afternoon wanted to see Favre play for another team.
The Packers said if Favre wanted to play for them, he had the chance when he told them a few weeks after his tearful goodbye news conference that he was having second thoughts. With Thompson and McCarthy preparing to fly to Mississippi and seal the deal on a comeback, all Favre had to do was say yes. He didn't.
"Ted always wanted Brett back," McCarthy said. "We always wanted Brett back."
In an interview with the AP on Saturday, Thompson called the situation "gut-wrenching."
"We understand where the fans are coming from," he said. "This is a hot-button issue that surpasses anything I've ever gone through."
The brothers, from the Milwaukee suburb of Pewaukee, started making random phone calls Saturday from the Green Bay white pages urging people to attend Sunday's rally and visit their Web site www.bringbackbrettfavre.com.
At the rally, they asked fans to vote on whether they wanted the team to make Favre the starter, whether Favre or Rodgers gives the Packers the best chance at the Super Bowl and whether Thompson should be fired if he trades or releases Favre.
The Web site is selling "Favre 08" shirts, bumper stickers and yard signs. Erick Rolfson, 32, plans to turn his Wauwatosa mortgage company into "Favre '08 Headquarters."
"Last time we checked," he said, "Green Bay is a publicly owned franchise and is owned by the people in the community and by the stockholders, not Ted Thompson."
Information from ESPN senior NFL writer John Clayton and The Associated Press was used in this report.