The 24-year-old suffered an ankle ligament damage against Bayern Munich on Tuesday and will be out of action for between two and three weeks.
It was feared Rooney could have missed the World Cup in South Africa.
“The nation can breathe again. We’re relieved,” explained Ferguson. “It could have been worse.”
Ferguson told Sky Sports News, when asked how long Rooney would be out of action: “Two to three weeks we think.
“Obviously in the two to three weeks he’ll miss important games, but the important thing for us is that he’ll be back before the end of the season.
“It’s the same for any player, you’re always hoping when they go for scans or X-rays that the results the news you’re getting it good.
“There’s no bone damage and there’s no serious ligament damage. Everyone wants their best players available.”
