England are confident their World Cup captain Phil Vickery will be fully fit for the tournament kick-off next month.
The Wasps prop was concussed in a midfield collision during England's 22-9 defeat against World Cup warm-up opponents France at Stade Velodrome.
Early signs did not look good as Vickery was carried off but the England camp remain positive about his recovery prospects.
"Phil is fine," said England head coach Brian Ashton. "I had breakfast with him this morning.
"The (England) doctor said to me you just do not know in these situations until 24 or 48 hours down the line.
"He said 50% of guys (concussed) in the Guinness Premiership play the following week, and the way Phil was this morning, the indication is he will be fine come the start of the World Cup."
England begin their World Cup campaign against the USA in Lens on September 8, followed by a crunch pool appointment with South Africa six days later.
Vickery spent several weeks sidelined last season after being felled by a punch in a Premiership game against Bristol, with concussion again being the medical diagnosis.
Vickery was not the only England player who failed to last the distance in a bruising encounter.
Leicester flanker Martin Corry limped off with a knee problem, while scrum-half Shaun Perry suffered a dead leg, joining casualties from England's Bath training base - flanker Lewis Moody (calf muscle) and scrum-half Peter Richards (back).
But Ashton added: "Martin wasn't over-concerned about it last night.
"The medics haven't seen him this morning, and I suspect had it been really serious then he would have been down very early to see them."