The lanky 26-year-old was included in Owen da Gama's U-23 squad for the event as an over-age player, along with Amakhosi goalkeeper Itumeleng Khune.
The Bafana Bafana regulars will join Da Gama's outfit for training sessions tomorrow and on Monday.
However, the pair will play in the annual Carling Black Label Champion Cup against Orlando Pirates at FNB Stadium on July 30 before flying to Brazil the next day, according to Chiefs' website.
"We have made an arrangement with the coach, Owen da Gama, and his technical team that the players will be released to join the Olympics squad after the Carling Cup,” said the club's football manager Bobby Motaung.
'Tower' is excited at the opportunity ahead.
“I am over the moon,” Mathoho said. “This is an opportunity of a lifetime. The Olympics is a stage that every player wishes to grace in their career.
“The Olympics offers one an opportunity to mix with top international athletes.”
The centre-back added: “Playing for Chiefs has really opened doors for me and the hard work pays as well.”
Mathoho is confident he will add value to the side.
“Even though age is a factor in sports, I think current trends show that even players as young as 17 can play in big leagues and teams. I am certain to make a contribution in the squad as well as learn from the experience.”