The defender-come-midfielder has been drafted into the Bafana squad which will face to Seychelles in back-to-back matches.
The two 2019 Africa Cup Nations (Afcon) qualification (Group E) games will be played later this month.
On Monday, Baxter, who is a former Kaizer Chiefs and SuperSport United head coach, announced a 24-man squad on Monday.
The English tactician has since added Modiba to the squad having worked with the 23-year-old player at SuperSport.
The South Africa Football Association (Safa) released the following statement:
"Bafana Bafana coach Stuart Baxter has beefed up his 24-man squad by including SuperSport United's upcoming and dynamic midfielder Aubrey Modiba to the squad to face Seychelles on October 13 and 16, 2018 in 2019 AFCON qualifiers."
"Modiba was one of the young players Baxter took to Zambia for the Four Nations tournament and was one of the key performers in this year's Cosafa Senior Men's National Team tournament that took place in Polokwane," the statement read.
Modiba, who was part of the SuperSport team that lost to Cape Town City in the 2018 MTN8 final last weekend, played for South Africa at the 2016 Rio Olympic Games.
Bafana will play host to the Pirates of Seychelles at the iconic FNB Stadium in Johannesburg on Saturday, October 13.
The return leg will then take place at the Stade Linite in Victoria on Tuesday, October 16.