Sir Alex Ferguson has reiterated his belief that England should not risk taking Wayne Rooney to the World Cup unless the striker has made a 100 per cent recovery from his broken foot.
The Manchester United boss admits his views are partly fuelled by a selfish desire to have Rooney back at Old Trafford fully fit for the start of next season.
However, he genuinely feels England should learn from David Beckham's below-par showing at the last World Cup soon after suffering a similar injury to Rooney's.
'To go to a World Cup tournament you can't have anyone half-fit,' Ferguson told MUTV. 'That's happened before in the past. I think David Beckham was not fit when he went to the World Cup (in 2002).
'What we've done with Wayne is assist him in every possible way. He's tried the oxygen chamber; he hasn't enjoyed it but he tried it.
'They've not got absolutely conclusive evidence the oxygen chamber actually works but there's nothing against it. Everything is worth trying and that's what we're doing with Wayne.
'He's in good hands. He's got the boot off and he's walking normally now which is good news.
'So you never know, but I certainly think it's very important for the boy not to go half-fit or even three-quarters fit and not do himself or England justice.
'A lot of people might think I'm selfish in that respect, but Wayne is the most important player in the team at Manchester United.
'We have to ensure the boy is going to be fit at the start of the season for us. We all become selfish in that respect.
'England are selfish and Manchester United are selfish because they want the best for their operation.'