Manchester United [Images] have brought forward England [Images] striker Wayne Rooney's [Images] next scan on his broken foot, warning the injury "involves a joint" and could take longer to heal than previously thought.

Originally scheduled for June 14, United and England have moved the scan to June 7 so that Rooney's fitness can be assessed before FIFA's June 9 deadline for replacing him in England's World Cup squad.

• Also read: Rooney broke more than a bone

"Both parties agree that everything possible is being done to aid the recovery of the fracture, which involves the joint," United said in a statement.

"Following a meeting today between England's medical team and Manchester United's medical team, with both managers present, it has been agreed to obtain a further precautionary CT scan on June 7 in order for the England management to make a decision before the deadline of June 9."

Worryingly for England coach Sven-Goran Eriksson and his hopes of taking the 20-year-old striker to Germany [Images], United also said on its website that 'involving the joint' meant: "an injury which takes longer to heal."

Eriksson, though, sought to play down the implications of United's statement about the fourth metatarsal of Rooney's right foot.

The Swede, who said United may still do a further scan on June 14, told a news conference that the switch "was my request, United understood the situation and accepted it.

"We will have a little bit better idea of the future."

As for the development affecting Rooney's World Cup chances, he said: "I'm always positive about it, optimistic...I'm not worried.

"I don't think it's a change at all. I was in the medical meeting today and I don't think it's anything new."

Rooney, who suffered the injury during United's Premier League defeat at Chelsea on April 29, is an inspirational figure for Eriksson's side.

FIFA rules state that Eriksson can replace him in the squad up to 24 hours before their opening World Cup game in Group B against Paraguay on June 10.

STANDBY PLAYERS

Bringing forward the scan means that if Rooney were to be ruled out of the finals, he could be replaced by a standby player, probably Jermain Defoe though possibly Andy Johnson.

Eriksson said he might take a standby player to Germany when the squad leave next Monday.

The England manager has always hoped that although recovering from injury, Rooney might be fit in time for the latter stages of the finals -- assuming England get through the group stage.

After the Paraguayans, England go on to face Trinidad and Tobago and Eriksson's native Sweden.

Rooney's absence from the finals would be a major blow to England's hopes of winning their first major trophy since the 1966 World Cup.

His place in the starting 11 alongside Michael Owen [Images] is expected to go to lanky Liverpool striker Peter Crouch.

Owen and Crouch are likely to start England's friendly on Tuesday at Old Trafford against Hungary, and possibly also Saturday's final friendly against Jamaica.

Eriksson would not be drawn on his team to face Hungary, saying only that it would be his strongest side and that "these two matches are very important for us."