"We have made good progress with the lad. The medical team have been fantastic but I'm not prepared to take a risk if the player isn't 100 percent fit," Ferguson told a news conference on Tuesday.
"We're looking at the Manchester City game (on April 17) and maybe Blackburn (on Sunday) as a substitute."
I don't think he will be on the bench (on Wednesday) although he might talk me into it, it is a difficult one," Ferguson added with a smile.
Rooney was in top form before the injury, scoring 34 times in all competitions including the opening goal in United's 2-1 first leg defeat by Bayern.
He is a key member of the England team hoping to win this year's World Cup in South Africa.
"It's been a hard season for the boy... we've only had him back a month into full training with the first team. I don't see him starting but certainly he can play a part," said Ferguson.
"He's on his way back and the boy's a terrific talent."
United have defender John O'Shea available again after a leg injury. The 28-year-old has not played since sustaining a dead-leg in Ireland's World Cup playoff against France in November.
