Reading vs. Arsenal: 6 Things We Learned in Capital One Cup

One of the most insane League Cup matches in the competition's history ended with Arsenal winning 7-5 after extra time against Reading in their Capital One Cup fifth-round tie at the Madejski Stadium.

A Gunners side featuring several fringe and young players was 4-0 down in the first half, but scored four of their own to force extra time. The Gunners had not held a lead during the entire regulation, yet scored first in extra time.

Reading then leveled to make a penalty shootout look on the cards, but two late goals from Arsenal provided a scintillating finale to 120 minutes of unbelievable football.

Here are six of the many things to take home from this remarkable match.

So often, cup competitions can provide a much-needed respite for teams who are struggling in the day job of league football, and for a while it looked like Reading were enjoying their temporary leave from their Premier League struggles.

The Royals are yet to win a game in the top flight this season upon their return from the second tier, but wins against Peterborough and QPR in previous rounds had at least given their fans something to cheer about.

But, despite seeing their team lead for more than 90 minutes, the home crowd saw yet another defeat for their team. Until the FA Cup third round gets underway in January, it's the hard slog of Premier League for Reading, starting with this weekend's huge bottom-of-the-table clash against QPR.

Arsenal have seen four-goal leads evaporate—they squandered one of their own in the thrilling 4-4 draw at Newcastle in February of last year.

They got a teasing taste of what it must feel like to mount such a comeback last season, when they came agonisingly close to cancelling out AC Milan's first-leg lead of 4-0 in the Champions League, but could only find three goals in reply at the Emirates.

After this incredible result, the feeling that anything is possible in football may be flowing through the Arsenal squad. Which is just as well—they travel to Old Trafford to face Manchester United on Saturday.

Arsene Wenger's policy of blooding young players in domestic cup competitions—especially in what is now known as the Capital One Cup—is well known.

Most of the big clubs have since followed Arsenal's lead of resting at least some of their best players for the least prestigious cup ties, but the Gunners have always been the the strictest followers of the concept.

However, Wenger perhaps went too far with his selection at the Madejski. Reading may be a team just come up from the Championship, but they are still a Premier League side. 

Handing a debut to goalkeeper Damian Martinez—who looked unconvincing all evening and had a role in a couple of Reading's goals—could have proved fatal on almost any other evening, while a first start for Serge Gnabry could have easily backfired given he has been part of two dismal defeats in the past week.

However, it is through competitions like the League Cup that clubs such as and especially Arsenal sort the wheat from the chaff and find out what their young players are really made of.

Coquelin is hardly a stranger to Arsenal fans—his start at the Madejski was his 20th for the club—and with almost every appearance the case for him being a future regular for the Gunners increases.

Often asked to fill in at full-back when injuries claim enough of the senior players, the French 21-year-old showed why he is one of Wenger's most trusted young players as he exerted his influence in the second half as the visitors got their act together.

Another young player who showed his mettle was Thomas Eisfeld, the German signed from Borussia Dortmund at the start of the year, who came off the bench to help engineer one of the the most memorable comebacks in English football recent history.

Olivier Giroud found out very quickly that it doesn't matter what you have achieved anywhere else, the critics will quickly surface if you do not get your Premier League career off to a flying start.

A couple of high-profile misses in his first few games as an Arsenal player this season led many to quickly write him off.

But he now beginning to show just why he was the joint top scorer in France last season, and why he was an integral part of the Montpellier side which claimed an unlikely Ligue 1 title last season. His headed goal two minutes after coming off the bench at Reading show there is plenty of potential in the France international to thrive for the Gunners.

Marouane Chamakh is another French import who has been consigned to the scrapheap by many an Arsenal fan, and with far more reason than Giroud.

The Moroccan got off to a great start to his Arsenal career, scoring 10 goals before Christmas in 2010, but since then he has looked a shadow of that player.

His late, two-goal contribution featured a neat finish from the edge of the box and a last-minute chip to round off Arsenal's comeback show that there is at least the prospect of fetching a good price for him if his future at Arsenal remains non-existent.

Elsewhere, Andrei Arshavin produced flashes of the player he was during his first few years at the club, even if many would rather his loan spell back at Zenit St Petersburg last season had been made a permanent deal.

His searing run down the left past tired legs in the dying minutes led to his shot being cleared off the line, but Theo Walcott was on hand to tuck home the rebound.