His decision to quit Celtic in the summer of 2019 caused anguish for many Hoops fans who thought he was on his way to becoming a true legend at the club.
It's hard to say he's not given the level of success he had after coming through the academy, but Kieran Tierney is showing he still loves Celtic a lot.
He's never hidden his support for the club and has spoken about how gutted he was that he couldn't stay in Glasgow.
Tierney was targeted by a section of the Celtic support who were heavily critical of his exit, with some even going as far as vandalising walls outside his house with graffiti calling him 'Judas'.
But the Arsenal star is clearly still madly in love with Celtic, as his shinpads show.
After the win over Chelsea on Boxing Day - when Tierney won a penalty - he shared a picture of his shinnies on social media.
One of them had the Arsenal badge and his No. 3 on them, and the other had the Celtic crest and his old No. 63 on it.
It's a sign of how important his time at the club was and how much he still cares about the Hoops, even when playing in one of the biggest and richest leagues in the world.
Arsenal have been struggling recently but former Rangers midfielder Mikel Arteta masterminded a 3-1 win over Chelsea on Sunday night.
Tierney was fouled to allow Alexandre Lacazette scoring the opener, before Granit Xhaka scored a stunning free kick and Bakary Saka sealed the win.
Jorginho missed a penalty for Chelsea, shortly after Tammy Abraham had pulled one back in the closing stages.
