Date of birth
The experienced defender joined Town on deadline day of the winter transfer window in 2022. He had played 25 games in Sky Bet League One for Sunderland, scoring one goal and assisting another from centre-back in the first half of the season.
Flanagan began his career with MK Dons, graduating to men's football in 2010. He first went out on loan to Kettering Town in 2011, where he spent four months with the Conference side. The Northern Ireland international returned to MK Dons at the end of the campaign and went on to play 21 times in their League One play-off reaching season. He went on multiple loans over the next four years, spending time at Gillingham, Barnet, Stevenage, and Plymouth Argyle - all in League Two baring the month with League One Stevenage.
Burton Albion came calling in 2015 and Flanagan moved up to the Midlands. He featured 18 times for the side that got promoted from League One and was even more involved in the next two Championship seasons, making 30 league appearances in 2016/17 and 27 in 2017/18. Throughout his three years with the Brewers, Flanagan made over 80 appearances, scoring twice and assisting twice. He also found a new lease of life and was utilised by Nigel Clough as a left-back for much of his time with Burton.
This form earned him a move up north to Sunderland where he spent the last three and a half seasons, making over 120 appearances and scoring five times.