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The signing of Kieran Tierney to Arsenal was orchestrated by Unai Emery, Then-manager of the club. Emery, who managed Arsenal from 2018 to 2019, identified Tierney as a promising young left-back and secured his transfer from Celtic in the summer of 2019. Tierney has since become an integral part of Arsenal's defense, known for his pace, tackling abilities, and attacking contributions.