England skipper Ferdinand has been plagued by persistent back trouble while striker Rooney suffered an injury-hit end to the season, with an ankle knock and a groin problem interrupting Manchester United's run-in.
But Red Devils boss Ferguson is confident both will be fit and ready to spearhead England's bid for glory in South Africa.
"Rio should be okay," he said. "He's had a spell in the last few weeks where we've nurtured him very closely and not pushed him until we get proper fitness in him.
"Once you've got that fitness, and he played for us on Sunday, there's no problem.
"Looking at the strikers in the world today Wayne is up there with all of them.
"Opponents will not be looking forward to playing against him, they'll be worrying about that because he's such a dynamic personality and player."
England boss Fabio Capello has yet to decide whether to pair Rooney with Emile Heskey, Peter Crouch or Jermain Defoe in attack but Ferguson insists he can lead the line alone if necessary.
"The challenge that Fabio's got is, he could play with anyone, but he can also play himself which is an advantage," he added.
"There are very few players who can do both. We've done it many times ourselves, playing him on his own because he's got such energy to cover the ground and the speed and power to play against the best."
Injury-hit Red Devils pair Owen Hargreaves and Gary Neville missed out on Capello's 30-man training squad, while veteran midfielder Paul Scholes turned down an invitation to come out of international retirement - a decision which did not surprise Ferguson.
"Owen has not had enough football so you couldn't honestly pick him, that's straightforward," he added.
"Gary has had injury problems over the last few years and I'm sure Fabio has taken that into consideration and he's well covered.
"Paul made his decision years ago. I think Fabio did the right thing to give him the opportunity to come back but he's established with his family, he enjoys his family life and I don't think it was a goer.
"He spoke to me and I told him to go with his gut instinct, and his gut instinct was to stay where he was."
Ferguson was tonight presented with the Virgin Active Outstanding Contribution to British Sport Award at the Sport Industry Awards 2010, receiving the trophy from Capello.