Newport County's Dublin-born captain Mark O'Brien has retired from football at the age of 27 as he requires heart surgery.
O'Brien, formerly of Derby and Luton, scored four times in 127 appearances for the Exiles.
The defender netted the winning goal against Notts County in 2017 which helped Newport avoid relegation from League Two and retain their English Football League status.
A Newport statement read: "The club will be doing everything it can to support Mark at this difficult time."
O'Brien was named the Ireland Under-16 Player of the Year in 2008. He underwent heart surgery a year later to correct a valve problem.
When he was 20, O'Brien suffered a cruciate ligament injury in training with the Rams, and then, having battled back to fitness, he was hit with another setback when he sustained an injury that required knee surgery.
He eventually moved to Luton Town in 2015, heading to Newport two years later.
O'Brien, alongside fellow Irishman Padraig Amond, enjoyed the most high-profile days of his career with the Welsh outfit, who took Spurs to an FA Cup fourth-round replay back in 2018, which they lost at Wembley. They had shocked Leeds United in the previous round.