Unal will however, be unable to play in the final due to getting himself sent off just six months after coming on in the second half.
NAC took a two goal lead against FC Eindhoven in the first half thanks to Uros Matic and Sjoerd Ars finding the back of the net but Unal had a game to forget after seeing red on 84 minutes.
Breda will take on Go Eagles in the final and play top-flight Dutch football if they win.
Unal could remain at NAC next season on-loan however, Pep Guardiola will take charge of City over the summer and may have other plans for the Turkish international striker.
The 19-year-old has nine goals in 11 appearances for NAC since joining on a temporary move in in January.
In 2013, aged 16, the City wonder-kid became the youngest player to score in the Turkish top flight scoring against Galatasaray.
Unal joined City on a £2,000,000 move after establishing himself as one of the most promising players in the Turkish league.