Mark O'Brien

Derby County

O'Brien started his career at Cherry Orchard, before he was spotted by Derby County scouts in the Dublin & District Schoolboy League. After signing for Derby, O'Brien became a regular in the club's under-18 team in 2008–09, before making his professional debut as a 64th-minute substitute for Lewin Nyatanga in a 3–1 defeat away to Watford on 3 May 2009. He was earlier named Derby County Academy Player of the Year at a club awards ceremony. He also won the 2009 Republic of Ireland Under-16 Player of the Year award. In November 2009, it was announced by Derby County that O'Brien had successfully undergone heart surgery to correct a valve problem, and that he would be able to resume his career following a three to four-month recovery period. The problem had been discovered during a routine medical scan for academy players. The operation was carried out at Leicester's Glenfield Hospital. Following a successful recovery, he was an unused substitute in Derby's final first-team game of 2009–10 as they ran out 2–0 winners against Cardiff City at Pride Park. In 2010–11, O'Brien returned to being a regular in the club's under-18 team and reserve team, and was also part of The Central League Central Division title winning team. O'Brien appeared twice for the first-team, both as late substitutes in league games against Barnsley and Ipswich Town in October and November 2010 respectively. On 6 August 2011, O'Brien made an appearance in the first game of 2011–12 season…

O'Brien has been capped at youth level for his native Ireland, at under-19 level. O'Brien was called up as standby at under-21 level for a game against Liechtenstein in November 2011. In January 2013, he was called up to the under-21 squad for the first time for a friendly game against the Netherlands on 6 February.

Derby County

The Central League Central Division: 2010–11 Individual

Derby County Academy Player of the Year: 2008–09 Republic of Ireland Under-16 Player of the Year: 2008–09 Derby County Community to the Club Award: 2011–12