Juventus' Mario Mandzukic (L) in action against Inter Milan's Miranda (R)
United have already splashed the cash this summer to sign Eric Bailly and Henrikh Mkhitaryan from Villarreal and Borussia Dortmund respectively, whilst free agent Zlatan Ibrahimovic has also joined the club in a blockbuster deal.
Yet, whilst the world focuses on United's pursuit of Juventus midfielder Paul Pogba, it seems that manager Mourinho is also considering adding more options in defence.
Monaco defender Fabinho
Right back Matteo Darmian had a solid if unspectacular debut season at Old Trafford, whilst Luis Antonio Valencia isn't a natural right back, prompting Mourinho to target another player in the position.
Globo Esporte report that Mourinho wants to reunite with Monaco's Fabinho, and United have opened talks to try and sign him before next month's transfer deadline.
Fabinho, 22, worked with Mourinho at Real Madrid, and whilst he was just a youngster then, he's now become one of the most promising right backs in European football having starred with Monaco.
Also capable of playing in holding midfield, Fabinho - who has four caps for Brazil - is an athletic defender with pace and strength, whilst he's also capable going forward and is a solid defender; but he may not be the only Brazilian international defender heading to Old Trafford.
The Daily Mail report that Mourinho wants to add an experienced head in the heart of defence, and he's eyeing up a move for Joao Miranda as a result.
Now, a deal would be complicated given that he's halfway through a two-year loan spell with Inter Milan, but parent club Atletico Madrid could cancel that if United offer up cash for a permanent deal.
The 31-year-old established himself as one of the top centre backs in world football with Atletico, and would provide the wily, veteran presence United need to pass on some knowledge to the raw and inexperienced Bailly in the heart of defence.
Would you like to see United sign Miranda and Fabinho?