Blatter has written a letter to the South African Football Association to express his sadness at the death of Phumo, who will be buried in Bloemfontein on December 11.
Blatter wrote: "Personally, and on behalf of FIFA, I would like to extend sincerest condolences to his friends and family, and the footballing communities in South Africa and Lesotho.
"Our thoughts and sympathy are with you at this time of sadness. He will be remembered for his dedication to both the men's and the women's game, particularly youth development, and his experience, knowledge and passion for the game will be sorely missed."