The 52-year-old, who also made over 200 appearances for the club as a player, was named interim manager in December 2018 following the sacking of Jose Mourinho. After a successful start he was handed the role full-time, leading the club for nearly three years before being dismissed in November 2021. After a lengthy spell out of the game, he returned at Besiktas in January 2025 but lasted just eight months before being sacked.
The decision to appoint Joey O'Brien as interim manager reflects the club's commitment to consistency and stability following Damien Duff's departure, ensuring a smooth transition during this critical period.