Mamelodi Sundowns aren't giving up the chase for Celtic's star defender, but a source says Chiefs are well on course to securing Mathoho's services after the player started training with the team.
"I can tell you now that I'm at Chiefs and Mathoho is training with the team," he reveals.
"In fact he is wearing jersey number 3," the source adds.
Chiefs boss Kaizer Motaung was quoted over the weekend saying it is a "done deal" for Mathoho.
However, Chiefs and Celtic are yet to officially confirm the move.
The source also says Kgotso Moleko is also at the club, which confirms recent reports that he has signed with the club.
Other new signings spotted in Naturena today are Kingston Nkhatha, who signed from Black Leopards.