Though United want to bring in a new left-back, there is currently a real lack of valid options who are either good enough or available to buy.
With Real Madrid missing out on Granada's Guilherme Siqueira to Benfica in the summer, Fabio Contraeo won't be leaving the Bernabeu any time soon unless a high-quality replacement can be found, as was the case back in September, according to BBC Sport.
In that respect they are in the same boat as United with regards to the short supply of realistic left-backs to target at present.
Chelsea's long-standing interest in Southampton's Luke Shaw, as reported in The Metro in 2012, suggests that the exciting young full-back is also off limits.
United will be reluctant to enter into an expensive bidding war with Roman Abramovich for the English prospect, who is seen by the Blues as the perfect successor to Ashley Cole.
Meanwhile, Leighton Baines also looks out of the question due to Everton's valuation of the England star, unless the player's own commitment to reunite with his former coach can push through a deal, as per The Independent.
When it comes to midfielders, Will Hughes may be the current flavour of the month, but Derby County have priced United and most of the player's other suitors out of the running with their demand for a £15million transfer fee, as per The Mirror.
Other gossip column regulars, Ilkay Gundogan and Ross Barkley, are out of the question in the short-term, with Jurgen Klopp desperate to prevent another one of his key players leaving after the loss of Mario Gotze and Robert Lewandowski's impending departure to Bayern Munich.
Barkley would be too costly considering the work that he must still do to round out his game, and Moyes' decision to hold the youngster back from first-team action at Everton last season suggests that any serious interest from Old Trafford may have dissipated with the retirement of Sir Alex.
When it comes to defenders, St. Etienne's Kurt Zouma is a target, but the player is unwilling to leave his current club unless he can be assured of first-team football to continue to develop, as per IBTimes.
United will be unable to offer the teenager such assurances at present with Chris Smalling, Phil Jones and Jonny Evans all vying for games behind Nemanja Vidic and Rio Ferdinand.