The Brazilians are said to have offered Ndlela to their neighbours, plus cash in exchange for Mphela.
Ndlela, who has not seen much action at Sundowns, will re-unite with his former coach at Moroka Swallows, Gavin Hunt.
However, Supersport United are also said to be delaying the deal as they want to offload Mphela to Europe, with France the reported destination for the Brits-born striker.
_quote“Sundowns have put in a great offer for Mphela. They are ready to make an exchange of players plus offering good cash to Supersport United.
"There are a few players that have been offered to Supersport including Lungisani Ndlela, which I think Gavin Hunt will be happy to have, having worked with him at Moroka Swallows,” said a source very close to the player.
“However, Supersport are still waiting for a deal to transfer Mphela to Europe and they are in talks with a team in France. If that deal in Europe doesn't work, then there is more than an 80 percent chance that Mphela will be joining Sundowns this season.”