Damien Duff has secured the 30-year-old former Sunderland man’s signature.

Former Sunderland, Millwall and Portsmouth attacker Aiden O’Brien has concluded a surprise switch to Shelbourne FC in Ireland.

The 30-year-old five-cap Republic of Ireland forward has linked up with former Chelsea and Newcastle United star Damien Duff, who now manages Shelbourne.

O’Brien signed for Sunderland while the club were in League One back in 2020 and stayed for two years, making 53 appearances in all competitions and scoring 11 goals, including a memorable hat-trick against Blackpool in the Carabao Cup back in 2023.

O’Brien was then infamously dropped by then-head coach Lee Johnson for Sunderland’s next league game following his Blackpool hat-trick. After leaving Sunderland, O’Brien has enjoyed stints at Portsmouth, Shrewsbury Town, Gillingham and Sutton United.

“I am pleased to join Shelbourne FC and embark on this new adventure," said O'Brien after concluding the move. "This decision was largely supported by the excellent staff and manager who helped me through the negotiation and made sure the deal worked for me and my family.

I have heard such good things about the team and can’t wait to be part of it. Moving to Dublin was a big decision; my grandmother was born there and I had a great relationship with her. It feels like the right decision for me and where I am in my career. I am ready to go and so excited to help bring this club back to where it belongs.”

Shelbourne manager Duff said getting O'Brien's signature was an "important moment, important signing. Exciting times, exciting player.”