The worst prognosis will be six months out if it is a cruciate ligament injury, but after the season that Michael Owen has endured the blow is so much crueller. As he dragged his injured right knee to the touchline this most undemonstrative of footballers was clearly in agony, and that was before he contemplated the end of his World Cup finals.
His World Cup is surely over; it may have flashed through his head that his career could be, too. But Alan Shearer said on BBC television last night that he had already received a text message from Owen promising that he would be back. Sven Goran Eriksson, the England manager, could only say that the striker "may be" out of the World Cup and that is likely to be confirmed today when the striker goes for a scan on his right knee.
"It didn't look good but I hope for him and for us it is not too serious," the England coach said. "He was getting better and better, but until we see the scan I cannot comment. It is a knee injury and I can only guess how serious."
It was a bizarre way to go. With less than a minute having elapsed in the match, and no Swedish player within a yard of him, Owen, by the left touchline, pushed off on his left foot, the toe of which seemed to stick in the turf. But it was his right knee that absorbed the pressure, flexing and twisting unnaturally. Owen improvised a frantic crawl over the touchline two yards away and then turned on to his back in agony. It was a dreadful moment for a player who broke a metatarsal bone on New Year's Eve and played only 27 minutes for Newcastle United in the rest of the Premiership season.
The television replays showed the appalling pressure placed on his knee, and if it is broken cruciate ligaments the return will be long and gruelling.
Rio Ferdinand was substituted on 56 minutes after complaining of a hamstring problem at half-time - Eriksson said he was confident that the Manchester United defender would be fit for the Ecuador game on Sunday.
In the stands, Owen's wife Louise rushed from her seat and down to the medical room to see her husband and the scale of his injury clearly had an impact upon his team-mates.
Wayne Rooney said: "Losing Michael is a real blow. Michael is a very important player for us and you know he will always get you goals. It was a big, big blow to see him injured but, hopefully, his scan will be OK."
Steven Gerrard, a former club team-mate of Owen's at Liverpool, said: "He's really down. We need to support him. It's not looking good."
With only Rooney, Peter Crouch and the as-yet-untried Theo Walcott now available as striking options to Eriksson, England cannot afford another injury. Eriksson protested that Gerrard and Joe Cole can still act as makeshift strikers and that he has "many who can fill that role".
Joe Cole said: "Losing Michael is a big blow for us as a team and our thoughts are with with him at the moment. He's had a difficult few months with the last injury he had and now it looks like he's going to have another difficult battle with another one.
"The thoughts of the players and staff are with him and his family, but no doubt he'll be back sooner rather than later scoring goals for Newcastle and for England."