The Red Devils boss has admitted that the centre-back may not be ready for a starting role yet and highlighted the need to rotate his squad with five games in 14 days coming up
The Serbian defender recently returned from three months out with a knee injury, appearing as a substitute in the 3-1 win over Sunderland at Old Trafford.
However, Sir Alex has admitted that Vidic may not be ready to make his first start since September, despite impressing on the training ground.
"Vidic might not be ready to start," he told reporters. "Vida is doing great in training, it's just a matter of picking the time to bring him back."
But while Vidic is still in contention, United are certain to be without Rafael at right-back, though Sir Alex is confident he has the resources to deal with the Brazilian's absence.
"Rafael is still out with a hamstring injury," he added. "But I have options [in the centre of defence] with [Chris] Smalling, [Phil] Jones, [Rio] Ferdinand and [Jonny] Evans."
The manager also emphasised the need to rotate his squad, with as many as five games upcoming for the Red Devils over the next 14 days, while he also praised Swansea in anticipation of a tough clash.
He added: "Utilising the squad will be important, as will picking the right team, but hopefully we can get through it and be in the same position as we are now.
"You've seen the results they [Swansea] have had and the progress they have made as a football club over the last years. The important thing for me is they try to play and have the courage to play their football, which is good."