"I know you Michael, you're a man, you're the best... This ordeal is your most difficult race but I am sure that you will win it too."
Michael Viehmann, president of a Michael Schumacher fan club in the small German town of Kerpen, where the retired racer grew up, said fans were "very upset".
"We know him really well. He's a fighter, we're crossing fingers that he will win this battle," he said.
The star's accident comes after several off-piste skiers died or were injured in the Alps, and on Sunday authorities in the Savoie department where Meribel is located asked skiers to be extra "vigilant".
Michael Schumacher, who won the last of his world titles in 2004, towered over the sport since his debut in 1991, winning more Formula One world titles and races than any other. He had a record 91 wins and is one of only two men to reach 300 grands prix.
His duels in his heyday with Damon Hill and Jacques Villeneuve, fired by an unquenchable competitive spirit, have gone down in Formula One lore.
Michael Schumacher was born in January 1969 near Cologne, Germany, the son of a bricklayer who also ran the local go-kart track, where his mother worked in the canteen.
By 1987, Michael Schumacher was the German and European go-kart champion and was soon racing professionally. In 1991 he burst into Formula One by qualifying seventh in his debut race in Belgium and a year later, he won his first Formula One grand prix.
He joined Ferrari in 1996 and went from strength to strength over the next decade, dominating the podium, before retiring aged 37.
During his retirement he survived a horror accident that knocked him out when racing a motorbike in Spain, though that time he was released from hospital after just five hours.
But the father of two could not resist the lure of the track and in 2010 he came out of retirement, signing a deal with Mercedes before quitting for good in 2012.
His helmet had a message for fans: "Life is about passions -- Thank you for sharing mine."