According to De Sa, the former goalkeeper is not only leaving the GladAfrica Championship side but the country as well.
When Dominic Isaacs was relieved of his duties by the Cape side, Petim took over on caretaker basis and was then succeeded by Maahier Davids.
"He is going to Portugal. He is going to live there, he is emigrating. He's got a house there, he's got family, so he's going to live that side," De Sa tells snl24.com/kickoff.
"He's leaving on Saturday. I mean I had him at Ajax for a long time, and now at Umoya. And he's always been very good."
De Sa, who said back in April that 50 percent salary cuts were being implemented at the club, shot down rumours that there were issues regarding salaries for Petim.
"No no no [laughs], not at all. He's got paid full salaries don't worry, everyone," De Sa assures.
De Sa also says there are currently no plans to fill the 34-year-old's position.
"Not right away. I think we'll wait till after the Covid thing. When we start with the new season we will obviously have to replace him but not now, it's too short notice. But we will do something when the season ends. I've got a young academy goalkeeper coach.
"It's always a loss, especially a guy like him that was a pleasure to work with and a very good club man, honest, straightforward, loves the game you know, he was a player. He was very much involved with the youth all the time and a good example to the older guys as well.
"So you know it's a massive loss, but good luck to him, he's got this fantastic opportunity to go live in Europe, and he wants to go now while he is still young. He's got little kids so obviously he's looking at the future of his children I suppose."
Petim, who played for Ajax Cape Town and Vasco da Gama, has dual citizenship.