England captain Phil Vickery will miss the World Cup games against South Africa and Samoa after a two-game ban for tripping USA centre Paul Emerick.
Vickery said his trip on Eagles centre Emerick was not malicious
The 31-year-old Vickery has 48 hours to appeal against the ban and the England camp are considering their position.
South Africa-born Matt Stevens will replace Vickery in the team to face the Springboks on Friday, with Perry Freshwater coming on to the bench.
The captaincy will go to Jason Robinson, Mike Catt or Martin Corry.
Vickery could have been banned for four weeks but for mitigating factors.
Tournament judicial officer Professor Lorne Crerar said his admission of guilt and previous good conduct merited a lesser sentence.
"The judicial officer deemed the trip was a deliberate act and was delivered with some force," said International Rugby Board spokesman Greg Thomas. "The opposing player had no opportunity to take remedial action.
"There were no aggravating circumstances and the JO took into account several mitigating circumstances including the immediate admission of culpability, the player's good character and his conduct during the hearing."
After Saturday's match, Vickery said of the incident: "It was unfortunate, he had made a good break. I was back tracking, like a good prop forward, always looking for the corner flag.
"He chopped inside me and it was just instinctive, trying to stop him. Unfortunately, I tapped him... There was no malice on my part."
Earlier on Tuesday, Emerick himself was suspended for five weeks, effectively ruling him out of the rest of the tournament, for a spear tackle on Olly Barkley in the 28-10 defeat to England.
The loss of the captain is another huge blow to world champions England, who began the defence of their title with an unconvincing win over the Americans.
The whole squad started mentally preparing for this game about six weeks ago
Jonny Wilkinson has an ankle injury while his fly-half replacement Olly Barkley picked up a hip problem in training.
In addition, Mathew Tait and Dan Hipkiss have been ill and in isolation since the weekend.
Vickery's suspension means Durban-born Stevens, who played for the Junior Springboks with the likes of Schalk Burger, Juan Smith and CJ van der Linde, will win his 15th cap against his native country.
He has already faced South Africa once before, when he was summoned at short notice from a holiday visiting his parents to start the second Test of England's tour this summer in Pretoria.
"It is a massive game and an even bigger one for myself, especially at a World Cup," he said.
"But I am not worrying too much about the peripheral stuff. The most important thing for me if I start is going through every detail because this match is going to be won on small margins.
"My background doesn't really come into it. I have been in England for almost six years, and I feel fully integrated in the England side. That is all I really care about - getting the job done on Friday.
"The whole squad started mentally preparing for this game about six weeks ago. We understand there is a lot of pressure on us to improve our game and we all realise we didn't achieve what we should have done against the USA. But we can and will do a lot better this week."