"No matter how much you practice penalties you just can't recreate it," the Newcastle United player was quoted as saying in Thursday's Daily Telegraph. "The penalty shootout is truly nerve-racking.
"In training you can bend them into the top corner but when you don't know where your legs are, when you've got to look down to see your legs because you simply can't feel them, it's totally different.
"No amount of training prepares you for that," said Owen, who underwent in the United States on Wednesday the first operation in a two-part procedure to repair the knee ligament damage he sustained in England's Group B game with Sweden on June 20.
England went out of the tournament in the quarter-finals, losing 3-1 on penalties to Portugal in Gelsenkirchen last Saturday.
It was the third time England had lost on penalties in a World Cup. They were also beaten by Germany in the 1990 semi-finals and by Argentina in the second round eight years later.
"They (penalties) are more nerve-racking than anything else in the game," said Owen.
"You've got 10 seconds before you put that ball down on the spot and it plays with your mind. You have to try not to think about it because there are so many questions.
"I've taken two in major tournaments for England and you really can't reproduce that pressure."
Wednesday's operation involved the repair of slight lateral cartilage damage in Owen's knee.
He now begins rehabilitation work before returning to Richard Steadman's base in Vale, Colorado in eight weeks' time for the second part of the procedure, which is to repair his ruptured anterior cruciate.