Darren O'Dea has joined Blackpool on a short-term deal.
The 27-year-old has been training with the club in recent weeks, and will remain with the Championship club until 4 January.
The Republic of Ireland international was most recently in Ukraine with Metalurh Donetsk, who he left in August.
He previously played in The Championship with Reading, Ipswich and Leeds.
O’Dea said: “I had a tough year in Ukraine, so I'm delighted to be at a good football club with good people, and I'm looking forward to getting started.
“I was desperate to play football again and I'm looking to now help the team.”
Want to say a massive thank you to everyone @celticfc ... The physios, staff and players were fantastic to me. A real family club! #hailhail
— Darren O'Dea (@odea_darren) December 4, 2014