bˈɔːɹn ɪn stˈɑːɹɹə zˈæɡoːɹə, ðə sˈʌn ʌv pɹəfˈɛʃənəl ɹˈɛslɚ pˈɛtkoʊ sˈɜːɹɐkˌɑːv, nˈæskoʊ stˈɑːɹɾᵻd plˈeɪɪŋ æz ɐ stɹˈaɪkɚ, plˈeɪɪŋ θɹˈiː ɡˈeɪmz fɔːɹ lˈɛvski sˈoʊfiəz fˈɜːst tˈiːm ɪn nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi, hˌævɪŋ dʒˈɔɪnd ðə klˈʌbz jˈuːθ sˈɪstəm æt ðɪ ˈeɪdʒ ʌv θˈɜːtiːn.
Born in Stara Zagora, the son of professional wrestler Petko Sirakov, Nasko started playing as a striker, playing three games for Levski Sofia's first team in 1980, having joined the club's youth system at the age of 13.