MONTREAL (AP) -- Formula One driver Robert Kubica was released from the hospital Monday, one day after a frightening crash at the Canadian Grand Prix left him with a slight concussion and sprained ankle.

"I feel very good," the 22-year-old said as he walked out of Sacre-Coeur Hospital. "I was very lucky."

Dr. Ronald Denis, the head of the trauma unit at Sacre-Coeur, was at the track and saw Kubica's car fly head-on into a wall during the 27th lap after coming into contact with Jarno Trulli's car.

"I was at the tower and to be honest with you, when I saw the accident I thought we were going to arrive there and he would be dead," Denis said. "But when we arrived there, he was talking to us, complaining of some pain in his right ankle. He was breathing, talking."

Denis said the force of the crash was significant but modern safety measures helped Kubica survive the impact.

"The way now the cockpit is built, the way the car is built, the way everything is built. The track is in very good condition to prevent major accidents like that.

"In our regular car, for sure we would have been dead."

Kubica hopes to be behind the wheel for Sunday's United States Grand Prix in Indianapolis. Denis said Kubica should be able to compete, but F1 will have to clear him.

The Polish driver said he remembers the crash but had not seen it on TV. He wasn't sure if he would seek out the video.

"I saw it when I was in the car," he said, giving a slight smile and a shrug.