Facing a scrum of reporters crammed into a hot and sweaty Ferrari motorhome eager to hear what the seven times world champion might say, Schumacher remained calm and called for understanding.
"Just before we start, because obviously a lot has been written and said in the press, I think that it is very obvious and very clear what we have communicated for many months," the 37-year-old said firmly.
"We will make a statement in Monza and this statement will be on Sunday... there is no point to ask any questions (about it) or get into it. Sunday is when it will be made clear and unfortunately not before."
Germany's mass circulation Bild newspaper reported on Wednesday that Schumacher would announce his retirement at Ferrari's home race, bringing down the curtain on the most successful career in Formula One at the end of the season.
Ferrari are also expected to announce that Kimi Raikkonen is joining from McLaren.
While Ferrari and Schumacher's closest circle have said nothing more than repeat their intention to reveal all on Sunday, fans are fearing the worst.
"Michael, I beg you, don't leave Ferrari," declared a handwritten banner festooned on the Monza grandstand on Thursday afternoon. "Without you, Formula One, like all the rest, will no longer exist".
"Kimi, red doesn't suit you," declared another.
A website (www.michael-please-stay-in-f1.com) has been set up, with messages pouring in -- including some hostile ones urging him to call it a day.
Renault's world champion Fernando Alonso, fighting Schumacher for the title with four races remaining, felt sure that his rival had made up his mind and would not be letting the media commotion affect him.
"I think Michael will concentrate on the race and on the championship," said the Spaniard, who leads the Ferrari driver by 12 points. "He made already the decision whenever, one month ago or one week ago, to stay or to go.
"That will not change too much his motivation or performance in the weekend, or the rest of the year. It is the same for Ferrari.
"We all want to win; Renault want to win, and Ferrari want to win -- Michael and me. It will not change anything."
Despite his earlier call for patience, Schumacher could not avoid all questions about his future. Asked whether he would not prefer to wait until after the end of the championship, Schumacher stonewalled:
"Next question," he replied.