Both players were widely linked with a move to Parc des Princes earlier this summer, and although talks eventually collapsed, the Ligue 1 outfit have kept up their interest
The Ligue 1 runners-up were widely linked with both players earlier this summer, but when it looked as though a deal for the Brazilian was imminent, Rossoneri president Silvio Berlusconi intervened, and the player subsquently signed a new contract at San Siro.
Meanwhile, Ibrahimovic has been vocal in his criticism of the running of the Italian club in recent months, but it has been repeatedly asserted that the Swede will be staying put.
However, the Lombardy outfit could well be tempted to cash in on two of their key assets due to their well-publicised financial problems.
"Milan have left the door open," an anonymous source told L'Equipe. "However, no negotiations have begun, and PSG have not positioned themselves yet."
Thiago Silva's lucrative new contract lasts until June 2017, while Ibrahimovic is tied to Milan for another two seasons, but both players are believed to be interested in moving to the city of Paris.
Milan CEO Adriano Galliani admitted that both men could yet leave San Siro before the end of the transfer window on August 31.
PSG have already brought in Napoli forward Ezequiel Lavezzi this summer in a deal believed to be in the region of €30m.