Retief Goosen, twice a winner of the US Open, was at the centre of a storm last night that could cloud next month’s Open Championship after he appeared to accuse Tiger Woods of play-acting.

The world No 1 won an epic US Open on Monday, only nine weeks after surgery to his left knee, often wincing with pain and limping around the spectacular Torrey Pines course near San Diego, California.

He is consulting doctors about whether he will be fit to play in the Open at Royal Birkdale, but even though Woods appeared to suffer while he laboured over five days to overcome Rocco Mediate, a 45-year-old fellow American, it seems that there may have been some suspicion in the locker-room that Woods was exaggerating his problem to gain the sympathy of an adoring audience.

Goosen was in the field at Torrey Pines, finishing in a tie for fourteenth, but when asked whether he believed that Woods was faking the extent of his pain, he said: “I think so. It just seemed that when he hit a bad shot his knee was in pain and on his good shots he wasn’t in pain. You see when he made the putts and he went down on his knees and was shouting, ‘Yeah’, his knee wasn’t sore.

“Nobody really knows if he was just showing off or if he was really injured. I believe if he was really injured, he would not have played.”

The South African was trying to soften the impact of his remarks last night, although he did not attempt to retract them, merely implying that he was not being serious. When approached by The Times on the eve of the BMW International Open in Munich, Goosen said: “I was being light-hearted. No one but Tiger himself knows how badly hurt he was. But if he was really badly hurt, he would have withdrawn, wouldn’t he?”

Goosen’s comments caused embarrassment at IMG, the management group that looks after the interests of both golfers, which would not make an official statement last night, but suggested that the South African’s remarks may have been misconstrued.

Doubt will plague any missives on the seriousness of Woods’s injury after he came from behind to win the dramatic 18-hole play-off at the first extra hole. It was his fourteenth victory in a major championship and moved him to within four of the record held by Jack Nicklaus.

However, if he is not fit for the Open, which starts on July 17, there can be no doubting the severity of his injury and Britain will miss one of the greatest sportsmen of all time from one of its sporting showpieces. If he is fit, the whispers will grow louder that the winces and grimaces that accompanied many shots last weekend at Torrey Pines were no more than playing to the gallery.

It is unclear what surgery Woods had in April when he went to Park City, Utah, but he has a long-term problem with his left knee that could affect his performance. Golfers need stamina, which has led to hours of training on treadmills for Woods. He is one of the most powerful drivers of the ball, but needs strength in his legs to maintain stability. Any long-term damage would severely diminish his power game.

Thomas Rosenborg, his surgeon, is thought to have removed damaged cartilage, but he performed another operation on the same knee almost six years ago when he drained fluid from the anterior cruciate ligament and also removed a benign cyst.

Any surgery is invasive and painful, even for a sportsman as fit as Woods. There is also no doubt that the left knee has been troubling Woods for some time. During some of the events towards the end of the season in the United States last year, he was seen pressing his leg against a cooler box to ease the pain.

Tim Vernon, the sports science officer at Sheffield Hallam University, which advises many European Tour golfers, said last night: “We don’t know how serious the operation was, but Tiger will need to be careful and consult his doctors properly to avoid doing any long-term damage. That will be uppermost in his mind before he makes any final decision whether to play at Royal Birkdale."