Arsenal's academy is renowned as one of the best for developing top players in recent years.
With so many top stars joining up with the Gunners on their road to stardom, it's hard to sniff at the job that the north London side have done when it comes to training young talent.
But among all of the success stories, there's always one who got away.
For Arsenal, that man is Serge Gnabry.
The young German winger came through the ranks at the north London club after arriving as a 16-year-old from Stuttgart.
He established himself as one of Arsenal's hottest prospects and even enjoyed a loan spell at West Brom as he tried to make the step up to playing at the highest level.
But with that loan switch not working out, the Gunners decided to move him on for a fee of £5million to Werder Bremen.
For a player who wasn't in Arsene Wenger's plans it seemed like a decent return, however three years later it appears that the Gunners may have for the raw end of the deal.
Gnabry is now a household name in German football, and has even established himself as a first team player with giants Bayern Munich.
As well as this, the former Arsenal man is a regular for the German national side, having picked up 10 caps along the way.
The latest cap came against Northern Ireland on Monday night where Serge Gnabry's lively display and last-minute goal acted as a timely reminder of what Arsenal missed out on when they let him go.
Here's what some of the Arsenal fans had to say on social media.
