The Serbian ace left the Red Devils over the summer on a free transfer to join Inter Milan after notching over 300 outings in a successful period with the Premier League giants.
But despite his credentials and experience, Vidic has struggled in Italy, and appears to have lost the confidence of San Siro chief Walter Mazzari – who has played him just eight times.
This has alerted Louis van Gaal, who is desperate to get in proven cover at the back.
The United chief’s defensive options have been decimated by injuries already this season, with youngsters Tyler Blackett and Paddy McNair having been used in key games.
Bringing Vidic back is thought to be seen as an option by the Dutchman, who is keen to get players in with Premier League know-how.
Zenit Saint Petersburg’s Ezequiel Garay is also a target, but the Argentine’s botched spell at Real Madrid is thought to be a concern.