In an interview with Bild newspaper on Tuesday, the Williams driver said he would not make a decision on when to return to Formula One for several days.

Images from the US Grand Prix

"I saw a few scenes on the hospital television -- that's it," he said when asked what he could remember of the high-speed crash in Indianapolis. "I can't remember anything else -- except for perhaps the start of the race.

"I can't remember how, where, when. There's nothing there. It's as if the scenes of the accident have been erased."

Schumacher crashed on the fastest part of the course at Indianapolis, spinning on the banking at turn 13 where speeds reach around 320 kph and slamming backwards into the wall before stopping in the middle of the track.

Medical staff spent more than 10 minutes extricating him from the shattered car. He was released from hospital on Monday.

Doubts remain over Schumacher's participation in the French Grand Prix on July 4. The German told Bild he was not thinking about a return yet.

"Right now I need some rest, just rest. At the earliest, in a few days, I'll be able to say what's going to happen next."

"At the moment, I'm definitely not thinking about motor racing," he said in the interview given before he flew home to Salzburg late on Monday.

"I just want to go home. I want to go to my wife and son."

Schumacher said he was all right considering the circumstances but had trouble sleeping and was suffering back pain.

"I had a severe concussion and a large bruise on my back -- that's what hurts the most. I try to sit rather than stand up or walk."

Former champion Niki Lauda, who was in a near-fatal crash in 1976, said Schumacher should get back in the car as soon as possible.

"As long as there's no pain he's got to start driving right away," the Austrian said in an interview with RTL television.

"He might have some muscle pain but that's something that can be taken care of fairly easily."

"In my era, drivers were getting killed every year. These days the cars and the tracks have been made very safe."

Last September, Schumacher missed the Italian Grand Prix at Monza after a similar high-speed crash in testing at the circuit left him with concussion.