The left-back is considering his options this summer after spending three years at Juventus.
He is already being tracked by United, who are putting together a formal offer, as Jose Mourinho is known to be a long-term admirer of the Brazilian.
And, according to Tuttosport, PSG are now fighting to Sandro this summer too.
The French champions looked at the 27-year-old a year ago, but they then binned plans to sign him during the January transfer window.
Now, though, PSG are ready to go back for Sandro by making a concrete offer during the current signing period.
Juventus, however, are desperate for the defender to stay and have offered him an improved contract.
Sandro has won the league and cup double in all three of his seasons in Italy. The only remaining major challenge for him left to achieve at the club is to win the Champions League, though he has now suffered multiple heartbreaks with Juve in the tournament.