Arsenal will reportedly target an up-and-coming left-back in the summer transfer window.
Cedric Soares, a right-back by trade, has been forced to deputise on the opposite side of defence in Tierney's absence, and the club allowed Sead Kolasinac and Ainsley Maitland-Niles to leave on loan during the January transfer window.
According to The Athletic, Arsenal are aware that they need to bolster their options at left-back, and they are committed to bringing in a new player in that position before the 2021-22 campaign gets underway.
The report adds that any signing would not displace Tierney as first-choice, so the club are hoping to welcome a highly-rated youngster to North London rather than an established defender who would command regular starts.
Cedric has put in a number of solid displays at left-back but was at fault for Ollie Watkins's winner against Aston Villa on Saturday, although Arsenal supposedly do not expect Tierney to be out for much longer.