Unai Emery could be set to make a big selection decision in the North London Derby against Tottenham.
Nacho Monreal's transfer to Real Sociedad was confirmed on Saturday, which leaves the Gunners a little bit short in the left-back department.
Kieran Tierney was signed from Celtic in a £25million deal this summer to be Monreal's long-term replacement.
But the Scotland international will not feature for the Gunners until at least October as he recovers from a groin injury.
Monreal had played every minute of every Premier League game this season, as Arsenal picked up six points from their first three games, but his departure offers an opportunity for other players to stake their claim for a spot in the first team.
Bosnian Sead Kolasinac has filled in at left-back before and is likely to be the one picked to start there against fierce rivals Tottenham in the North London Derby at the Emirates on Sunday.
That is of course, unless Emery decides to make a tactical change and go with three at the back instead - which seems unlikely.
But could Emery hand a start to a young gun from the Arsenal academy?
Bukayo Saka has been training with the first team this week - not out of the ordinary for the 17-year-old, who has been involved on various occasions before.
He made one Premier League appearance last season in the 4-1 win over Fulham on New Year's Day, and was an unused substitute on two other occasions.
Arsenal's U18 sider were in action against Southampton on Saturday, while the U23s took on Derby County in the Premier League 2 on Friday night, with Saka involved in neither match as he trained with the first team.
And his omission from those two matches suggests he is set for a place on the bench against Spurs, as Kolasinac's understudy at left-back, a position he has played for the age groups at international level with England.
