The South Africa international played for Sundowns before joining Russian outfit FC Rostov in 2012.
The Tshwane giants wanted to sign him upon his return from Europe in 2015, but Xulu chose the club he played for as a young boy.
Xulu is among the seven players who were 'released' by Amakhosi last week, but he still hasn't the club due to unresolved issues between the him and the club.
Goal revealed last week that Cape Town City were very interested in the 25-year-old, but with more teams now interested, they will have to put an enticing offer on the table.
The KwaMashu-born defender hardly enjoyed his football over the last seasons, with Steve Komphela using Erick Mathoho and Lorenzo Gordinho more at centre-back positions.
Xulu turned down a move to Major League Soccer (MLS) during the January transfer window, but little did he know that Amakhosi were planning on offloading him.