The Frenchman told reporters after his visit that he had spoken with doctor and mutual friend Gerard Saillant who said Schumacher, now 45, is "out of danger".
"He (Saillant) said it is a serious condition but his life is not in danger any more, thankfully," Streiff said.
He also provided new details of the German's injuries, including the apparent risk that the former Ferrari and Mercedes driver could be left "hemiplegic", or paralysed on one side of the body.
He also said the nature of the bleeding on the sides of Schumacher's brain endangers Schumacher's speech and motor skills, but Streiff's comments were dismissed by manager Sabine Kehm as "pure speculation".
Kehm insisted her boss remains in a "critical but stable" condition, and Streiff later told France's RMC that Schumacher is in fact in "a stable but serious condition without deterioration or improvement".
It is believed that the doctors in charge of Schumacher's recovery could give a full medical update to the media on Monday.
At the same time, French authorities are investigating the circumstances surrounding Schumacher's skiing fall, which was reportedly captured by video on an eyewitness' mobile phone, who said the German was travelling at no more than 20kph when he hit rocks and struck his head.
The authorities issued a statement urging the media against "spreading false information" about the investigation, according to France's L'Equipe.
Nonetheless, the respected Sunday newspaper Le Journal du Dimanche cited hospital sources in claiming the most recent brain scan undergone by Schumacher had "very bad" results.
And Kehm denied that the Schumacher family only reluctantly gave up the 'Gopro' camera that was attached to his helmet. It is not known if the camera was recording at the time of the crash.
"The family gave the camera to the investigating authorities voluntarily," Kehm is quoted by Bild newspaper. "That this was done against the wishes of the family is untrue."
Finally, Dr Johannes Peil, who treated Schumacher in 2009, revealed that an artery in the driver's brain was damaged in that serious motorcycle crash.
He said the old injury should not affect Schumacher's recovery now.