Anthony Martial has been out since December 9 and will be missing for at least another 10 weeks following a groin operation, leaving Rasmus Hojlund as the team's only fit centre-forward.
Red Devils head coach Erik ten Hag said on Friday that there was no room in the budget to bring in a striker, with the club restricted due to the rules surrounding Financial Fair Play.
However, according to HITC, a possible option has opened up in the shape of Braithwaite, with the experienced forward being offered to the 20-time English champions.
The report claims that Chelsea, Arsenal, Fulham, West Ham United and Wolverhampton Wanderers have also been made aware of his availability before the end of the January transfer window.
Braithwaite has previously played in England for Middlesbrough, turning out at the Riverside Stadium between 2017 and 2019, scoring nine times in 40 appearances.
The forward then represented Leganes ahead of a switch to Barcelona, and he scored 10 times in 58 appearances for the Catalan side in all competitions.
Braithwaite made the move to Espanyol in September 2022, penning a three-year contract, and he has played 56 times for the Catalan side, scoring 21 goals and registering three assists in the process.
The Denmark international has been in impressive form in the Segunda Division this season, scoring 11 goals and registering one assist in 21 appearances in the second tier of Spanish football.
Braithwaite has a contract with Espanyol until the end of next season but will allegedly be allowed to depart before Thursday's transfer deadline.
At this stage, it is unclear whether there is any interest from Man United, or whether the forward is available on a permanent basis or a short-term loan.
Ten Hag said during his press conference on Friday that Marcus Rashford would be used through the middle when Hojlund is not available or rested.
However, Rashford could be facing disciplinary action from the club, with the England international being spotted at a nightclub in Belfast the night before he missed a training session at Man United through illness.
On Friday, Ten Hag confirmed that Rashford, who has struggled to show his best form for the Red Devils this season, was a doubt for Sunday's FA Cup contest with Newport County due to illness.