Rooney injured a knee ligament in training and missed United's holiday fixtures against Newcastle United, West Bromwich Albion and Wigan Athletic as well as their FA Cup draw at West Ham United.
"Wayne Rooney is still out," Ferguson said. "I am hoping he will start training today actually, in which case he won't be far away. I don't think it is an issue, but we need to guide him along.
"In terms of the injury he had, it's quite straightforward so if he starts today, I assume he will be available for Wednesday's replay (against West Ham)."
United winger Nani and midfielder Anderson will both return to the squad for Liverpool's visit to Old Trafford.
"Nani is back in training and will be included in the squad for Sunday.
"Anderson has been back training for 10 days now so he will be in the squad for Sunday. All in all it is quite a positive situation. It's good to have them back."
United lead the Premier League by seven points from local rivals Manchester City after 21 games, while Liverpool are 14 points further adrift in eighth place.
The fixture, however, remains as important as ever, according to Ferguson.
"The derby game against Liverpool never changes," he said. It's always an immensely important game - intense, emotional. We are going into the game in reasonable form."