Mphela, whose nickname is "Killer", was arrested early Monday when police stopped his Audi during a routine patrol in the upscale Johannesburg neighbourhood of Sandton, said police spokesman Lungelo Dlamini.
"The officers were on their normal patrol. They stopped the car and then spoke to the suspect and discovered that he was drunk," Dlamini told AFP.
Mphela was taken into custody for four hours before being released on 1,000-rand ($145, 100-euro) bail, Dlamini said. Police are waiting for the results of a blood test.
Mphela scored the only goal in South Africa's 1-0 victory over Egypt on Saturday, clinching a last-minute win for Bafana Bafana in the 2012 Africa Cup of Nations qualifier in Johannesburg.
Dlamini said the striker would appear in court on October 4.