Matthews confirmed that they would send winger George Lebese back to Sundowns with his loan deal set to expire at the end of June.
Lebese made seven league appearances for Matsatsantsa and is set to return to the defending Absa Premiership champions.
Matthews said they would try and negotiate for Mohomi and Ngoma to move to United next season after Lebese didn’t do enough to earn a permanent move to Matsatsantsa while on loan.
Sundowns would like to lure Tebogo Moloi and Aubrey Modiba from United but Matthews said they would only sell him to an overseas club. SuperSport turned down a reported multi-million rand offer from Sundowns for midfielders Moloi and Modiba.
Ngoma and Mohomi have been linked with a move away from Sundowns after failing to command a regular starting berth since joining the Brazilians two season ago.
“We will try and see if we can’t sign Lucky Mohomi or Aubrey Ngoma from Sundowns,” Matthews told SowetanLIVE.
“If it doesn’t happen we have a couple of back-up options.”