According to Simon Mullock of the Sunday Mirror, Red Devils boss Jose Mourinho believes the Brazil international is the ideal man to solve his team's left-back issues.
Mullock noted Chelsea's longstanding interest while also suggesting the Italian champions value the left-back at around £53 million.
"United's interest is unlikely to be firmed up until the summer, but they could be prompted to enter the market earlier than planned if [Blues manager Antonio] Conte is able to convince his Chelsea bosses that the 26-year-old is worth the money during the current transfer window," Mullock added.
The Red Devils have had numerous players attempt to establish themselves at left-back this season, although there's been no standout candidate.
Earlier in the campaign, Ashley Young filled in well, while Daley Blind and Matteo Darmian were also handed opportunities in the position. Most recently Luke Shaw has shone in the role, having been out of favour at the start of the season.
As football writer Liam Canning noted, the former Southampton man has benefited from a recent run of games:
Nevertheless, it would be no surprise to see United move for another left-back, as Mourinho has evidently had reservations about Shaw in the past.
Sandro would offer something extra in the position, as he's been exceptional since arriving at Juventus from FC Porto in 2015. At times, he's been the best left-back on the planet.
The 26-year-old offers a lot. Defensively, he's tenacious, and his relentless energy sees him cover his centre-backs in addition to tracking runners vigilantly. Sandro's industry also sees him push forward regularly and make an impression in the final third.
While he's not been at full throttle this season, these numbers from WhoScored.com show the type of multifaceted footballer Sandro is:
Chelsea's interest in the Brazilian makes sense, as the Blues lack left-back cover behind the excellent Marcos Alonso.
United have the financial muscle to match Chelsea should they launch an offer for the player in January or in the summer. According to Mullock, Paris Saint-Germain have also showcased an interest as of late too, which may be a big concern for the two Premier League sides.
Writer Arjun Pradeep suggested Sandro may benefit from a fresh challenge given his fluctuating form this term:
If United are eyeing a new left-back, then they should be looking to bring in someone who would be a major upgrade at a weak area of the squad. And in Sandro, they would be getting one of the best.
Still, any deal would be far from straightforward if Conte's Chelsea are sniffing around—and especially if PSG muscle their way into the battle. Plus, there would surely be a reluctance on Juve's part to cash in on a footballer who would be difficult to replace.