Born in Cork, Bradnock-Brennan started his career in England with Fulham and then Blackpool, where he was signed on professional terms in 2011.
However, the centre-back was released by the Seasiders after a year and returned to London to join Bostik League Premier side Harrow Borough.
After a season at Earlsmead, Bradnock-Brennan accepted a college soccer scholarship at the University of North Carolina and was highly-rated in his junior year.
He earned national honours in being named in the team of the week for the Charlotte 49ers and named one of the top ten defenders in college in the same year.
After three years at college, Bradnock-Brennan signed for United Soccer League side San Antonio and finally left the States earlier this year when he signed for Norwegian outfit Os Turnforening