Concannon was born in Hagley, Worcestershire. He joined Birmingham City F.C.'s Academy at the age of seven, worked his way up through the youth system, and took up a two-year scholarship in July 2016. Academy coach Steve Spooner described him as "a very good central midfielder that has great understanding of the game both technically and tactically a good engine competitive". In his first year, he scored four goals in 19 appearances for Birmingham's under-18 team, and in his second, he helped Birmingham's youth team reach the semi-final of the 2017–18 FA Youth Cup, and played in both legs as Chelsea outclassed Birmingham 7–0 on aggregate. Where other second-year scholars were offered professional contracts, concerns about Concannon's lack of physicality meant he received a third scholarship year.
Loan spells
Concannon was anxious to go out on loan to demonstrate his ability to cope physically in men's football, and signed for Sutton Coldfield Town of the Southern League Division One Central on work experience in August 2018. He moved up a level to join Southern League Premier Division Central side Tamworth on an initial one-month loan on 14 December 2018. He made his Tamworth debut on 22 December in a league fixture at home to St Ives Town, which the away side won 2–1, and coped sufficiently well with men's football that his loan deal was systematically extended to the end of the season, during which he scored five goals from 21 league appearances. The club's manager, Gary Smith, was appreciative: "He's been a fantastic player for us, someone with a great attitude and appetite for the game. He's still learning and growing in stature but he has been absolutely fantastic – a really clever player with great feet."
Return to Birmingham City
On 24 May 2019, Concannon signed his first professional contract with Birmingham City, of one year. He was an unused substitute for the first team on 1 February 2020, and made his competitive debut for Birmingham three days later in the starting eleven for the FA Cup fourth-round replay against Coventry City. He was booked for a foul after 26 minutes and was substituted after 57 minutes for Jérémie Bela. The score was 2–2 after extra time, and Birmingham won the tie on penalties. Concannon signed another one-year contract in July 2020.
