#1 Kieran Tierney

With an ageing Nacho Monreal and Sead Kolasinac consistently on the treatment table, Arsenal needs a new left-back for moving their team forward. Celtic's Kieran Tierney is currently among the best young left-backs in the world and would be a great addition for the Gunners.
The 21-year-old Scot is an attacking fullback who is a threat going forward and unlike many attacking fullbacks, he is defensively sound as well. He played 90 league games for Celtic thus far, scoring five times.
He won three Scottish Premiership titles with the Scottish giants and was the part of PFA Scotland Team of the Year (Premiership) on two occasions. He has won three PFA Scotland Young Player of the Year awards along with one Scottish Player of the Month accolade.
Kieran Tierney was linked with Arsenal last season and the Gunners could turn their attention towards the talented youngster once again for fixing their left-back position for the years to come.