Both forwards were sent out on loan after joining, to Le Havre and Villarreal respectively, in order to prepare them for next season.
United and Chelsea were both in the market for new strikers in January, but only the Red Devils managed to add to their attacking options.
Ole Gunnar Solskjaer signed Odion Ighalo on loan from Shanghai Shenua until the end of the season, as he looked to replace the injured Marcus Rashford.
Ighalo is in line to make his first appearance for United when they travel to Chelsea on Monday.
