Sithole, 19, a product of the esteemed KwaZulu-Natal Academy, joined Sporting last year and featured in the club's U19 side and during their UEFA Youth League campaign over the course of the 2017/18 season.
However, the KZN Academy have since confirmed that the talented midfielder has signed for domestic rivals Vitória de Setúbal, where he is likely to feature within the club's U23 side.
Meanwhile, he will be joined by two further KZN Academy graduates, in the form of Amajimbos defender Nkanyiso Shinga and Philani Jaca who impressed during the club's recent tour in Portugal.
Both teenagers will be included in Vitoria's U19 side for the upcoming season.
We wish Sphephelo, Nkanyiso and Philani all the best as they showcase their talent and may they bring their new experience to oyr national teams. pic.twitter.com/vGoq6tYuCW— KZN Academy (@kznacademy) August 15, 2018