 Upon joining the club, Tasci said it was a dream for him to play in Turkey.Tasci made his debut, playing the full 90 minutes in a 1–0 win over Hatayspor in the first leg round of 16 of the Turkish Cup.It wasn't until 18 February 2019 that he made his league debut for Başakşehir, playing the entire match in a 1–0 win over Antalyaspor, for which he earned the praise of the Turkish media.