PSG and Mbappe have become embroiled in a battle over claimed outstanding wages owed.
Former Liverpool defender Sakho, now with Georgia's Torpedo Koutaissi, told Canal+: "PSG knows how to welcome but has trouble saying goodbye. I find it a shame but it's a fact. When you see the welcome given to Ibrahimovic, Kylian (Mbappé), Neymar, Messi, and the way they leave, it breaks my heart.
"I see a football club as a family. It's like celebrating a birth. When a player arrives, we're all happy. When that child you spent years with grows up and decides to leave the family cocoon, you have to accept it and know how to say goodbye .
"When I presented the champion's trophy to PSG last season, I felt a pang in my heart to see this fantastic player leave through the back door with all that was said about him. I personally found it a shame. You have to know how to separate business from football
"Kylian Mbappé is a diamond that has value. He earns astronomical sums but he generates just as much. No one earns a euro if they are not worth it. That is up to his parents, his advisors and the club's directors. I think that Kylian as a football player has entered every Parisian home, every house in France. He has made young people in training centres and schools dream. We must thank him for that and realise how lucky we were to have him in our stadium and in our capital. He carried our French colours high, and he continues to do so, and at Paris Saint-Germain."