Vidic's return would provide a real boost ahead of the midweek encounter against Champions League opponents CFR Cluj.
"I knew Vida was doing really well with the physios," explained Sir Alex. "He was doing his football training with them in terms of turning and striking the ball but he came into training last Monday with the first team and did okay.
"He's a battler, an absolute competitor. He's got that dour, uncompromising way of his. He likes defending - that's what he does."