Vidic has been out since September following another bout of knee surgery and, while Ferguson has not decided whether to start with the Serbian at Old Trafford, he confirmed it was a major boost to have him back.
"Nemanja is back in the squad," said Ferguson. "He is a top defender and our captain."
Ferguson also confirmed Shinji Kagawa would begin training with the first-team again after a two-month absence. However, Jonny Evans has been ruled out of Saturday's game with a hamstring injury. "I felt it would be a problem for Jonny at the start of the second half last week," said Ferguson.
Team-mate Darren Fletcher is amongst those cautioning against expecting too much too soon of Vidic though. Fletcher had his own long spell on the sidelines with the chronic bowel complaint which threatened his career and three months on, the Scot is still feeling his way back.
" Nemanja Vidic has had a tough time," said Fletcher. "He has almost missed a year of football. We know the strength of character and determination he has and the quality he has.
"He has been back training in the last few weeks and the manager has spoken about maybe playing him against Sunderland. He will need a few weeks to get back into the routine of things but he is such a massive player for us he will be important if we want to achieve success this season."
Meanwhile, Ferguson insists revenge will not be a factor for his side when they face the Black Cats.
The United camp were irritated at the way Sunderland fans reacted so gleefully when Sergio Aguero scored his injury-time winner at the Etihad Stadium to earn Manchester City the title last term. After beating Sunderland at the Stadium of Light, the Red Devils players were still on the pitch when Aguero's strike went in.
"It was disappointing given the number of players we have given them down the years, but there was no malice in it and there is no element of revenge," said Ferguson. "Winning the game is more important for us given what we achieved last week. Now we really need to kick on and make sure we retain our lead at the top of the league."