The Burundi international, who is 22-years-old, was recently linked with a move away from the National First Division (NFD) club.
However, Cosmos moved swiftly to offer Nsabiyumva a two-year contract which he signed, before his previous deal expire at the end of last month.
According to The Citizen source, AmaZulu and Pirates still interested in the towering defender ahead of the 2017/18 season.
“I think it will depend on the player because Jomo has told him that he doesn’t have a problem with him leaving and is awaiting on the teams to make offers," the source said.
"He will take any offer just as long as the player is happy with it,” the source continued.
“There are two or three players Pirates are looking at offering Cosmos in exchange and that will put them in good stead to land the defender,” the source concluded.
The former Atlético Olympic Bujumbura player made 30 appearances in all competitions for Cosmos during the 2016/17 season - netting four goals in the process.
Bucs are expected to bring in new defenders as they had one of the worst defences in the PSL - having conceded 40 goals from 30 matches.