Date of birth: June 5, 1997
Instagram: @kierantierney
Club(s): Celtic, Arsenal
Country: Scotland
Signing fee: £25 million
Was just 17 when he made his first-team debut for Celtic having progressed through the academy. Four years later, he left having won four Premiership titles, captained the club and been part of the historic treble treble winners. But injuries restricted his appearances in Glasgow - and in London after his move to Arsenal. Due to the presence of fellow left-back Andrew Robertson, he has had to play in a variety of positions for Scotland.
