You may be looking for the master thrall from Triskelion named Galt.

Gault was a Federation colony with a sparse population of no more than 20,000 inhabitants. It was widely regarded as a "farm-world". (TNG: "Heart of Glory")

In 2347, Sergey and Helena Rozhenko moved here with their two sons, Worf and Nikolai. One of the secondary schools on Gault had a soccer team which Worf captained in 2353 at the age of thirteen. (TNG: "Homeward"; DS9: "Let He Who Is Without Sin...")