3. Cheap and available
Bringing in Vidic for a year or a year and a half would be the best deal for Manchester United. They would have to pay a fee to Inter Milan but that should not be a huge amount to get a 33 year old defender back. Vidic was always loved by the United faithful and could do the job for Manchester United especially with the injuries that have hit them this season.
Chris Smalling is the latest player to suffer an injury and Marcos Rojo had already faced time out from the team a month back, so a cheap and known player who is willing to come back to United makes sense. Plus he wouldn’t have to play in midweek fixtures which would certainly help his performance.