The Norwich City and Arsenal players first met at Celtic.
Norwich and Arsenal met at Carrow Road on Sunday, sharing the spoils courtesy of a 2-2 draw.
Even though Roberts and Tierney remained unused substitutes in Norfolk, they were still captured together on camera.
And Roberts added a photo of the pair to his Instagram story earlier, which contained a nod to their Celtic pasts in the form of a green heart.
Former teammates Patrick Roberts and Kieran Tierney enjoyed a Celtic reunion on Sunday. pic.twitter.com/eTaw8FsEEr— Footballer Instagram Stories (@BallerStories) December 2, 2019
Roberts - a regular as Celtic won three successive Scottish Premiership titles between 2016 and 2018 - has only played 113 minutes of first-team football for Norwich this season, after arriving on a season-long deal from Manchester City.
Tierney has fared somewhat better at Arsenal, playing 696 minutes despite having arrived at the Emirates Stadium injured.
Celtic fans - would Roberts and Tierney be better off in Glasgow?
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