With Rashford expected to miss roughly six weeks due to a stress fracture in his back, manager Ole Gunnar Solskjaer admitted that United may need to look for a short-term solution.
That solution won't come in the form of Alexis Sanchez, though, as the club didn't insert a recall option in his loan deal with Inter Milan, reports Rob Dawson of ESPN. Sanchez, whose campaign at the San Siro has largely been derailed by an ankle injury, joined Inter on a temporary basis last summer.
With the January transfer window quickly approaching its end, United could be left scrambling to replace Rashford's production. The Englishman, 22, leads the team with 19 goals in all competitions this season.
Talks have been ongoing between United and Sporting Lisbon over a move for attacking midfielder Bruno Fernandes, though the two sides reportedly remain at odds over their valuation of the Portuguese international.
Negotiations over Fernandes are slated to continue this week, according to Dawson.