Mahamutsa and Teyise had been training with Ea Lla Koto for several weeks following their respective exits from Orlando Pirates and SuperSport United in the off-season.
Stars chairman Mike Mokoena hopes the duo's arrival will see the team stop conceding "embarrassing goals", as was the case in the 4-1 loss to eventual Telkom Knockout champions Cape Town City on November 26.
Mokoena tells KickOff.com: "It is true that we have signed them. I just hope we will stop conceding stupid goals like we did against Cape Town City.
"If you check our goals against Cape Town City they were all embarrassing, so I hope that department will be okay."