When a baby faced Theo Walcott rocked up at Arsenal's London Colney training base in January 2006 to complete a deal from Southampton, the football world tipped him to be England's next hope.

Flash forward twelve years later and Walcott is now an Everton player with a career that for a whole host of reasons hasn't lived up to its hype and expectation.

He departs Arsenal now with a fresh look from his teenage days; a beard and slicked back hair - but it's a difference which unfortunately hasn't been in tandem with his football career, because for Walcott, there has been little change in his development as a 16-year-old footballer to a player now in the prime of his career.

However despite Walcott leaving London behind with his career still to take off, he exits as one of Arsenal Football Club's most underappreciated players.

Mismanagement

Walcott arrived in the capital for £5m, a fee which even now for a 16-year-old sounds rather expensive. However the price tag came with glowing reports of a player who could one day become an England great.

English players are often over hyped and it's hard to argue that one of it's most typical cases comes in the form of Walcott, whose career hasn't even come close to the dizzy heights that many expected when he burst on to the scene at Southampton.

But what are the reasons for this? Much of it can be down to a huge mismanagement of a player who came into the limelight way too soon.

Walcott was playing in the Championship before his move, but five months later would be named in Sven Goran Eriksson's World Cup squad at 17 without even making a single Premier League appearance.

Remarkably that still stands as the only World Cup he has ever been to, missing out in 2010 when Fabio Capello decided not to select him and then in 2014 with an ACL injury.

However for the success stories that Arsene Wenger has produced at Arsenal - Cesc Fabregas being the main man that springs to mind - Walcott is his biggest failure and much like his own manager has dwindled away in recent seasons.

Being selected for a World Cup at just 17 was an extreme misjudgment, but Walcott's move to Arsenal also came too soon, and the expectations were thrust on him far too quickly. At such a young age being thrown into the first team of one of the country's best club's he lacked the guidance his game needed - and for that reason his career has stalled and stuttered without getting out of third gear.

Now 28, he is a player who still looks as though he's trying to learn the game and a large contributing factor is his mismanagement as a youngster by those around him. Because of that Walcott will go down as simply an underappreciated player at Arsenal, rather than the potential tag of greatness that burdened the early stages of his playing days.

Trying to recreate an Arsenal great

Perhaps the worst thing to happen to Walcott's Arsenal career was the comparison with Thierry Henry. An Arsenal player with pace who played out wide but had the potential to move up front was always going to be compared to Henry - and picking the number 14 shirt in 2008/09 didn't help that either.

But the biggest issue Walcott had during his Arsenal career was wanting to play up front when he was better out wide. His finishing ability has always been a bit inconsistent and it's that final delivery which he's never seemed to develop over the course of his career; you always sense he isn't quite sure what to do with the ball when he receives it - rather than being fearless and using his pace to his advantage.

That has been the problem with Walcott for far too long and shows why eventually Wenger lost patience with a player who was one of his most loyal servants.

However Walcott deserves great respect from Arsenal fans. Never once did he complain and not once did you see him act unprofessionally. He went about his business in a quiet way but that inability to come out of his shell offers another reason for his lack of success.

Henry's personality was of course in stark contrast, and Walcott being compared to him from a young age was another burden he didn't need. Henry left the club a legend, the same cannot be said for Walcott who walks away from Arsenal with an underappreciated tag across him.

'Sign da ting'

A number of years ago there was a sense that Walcott was finally starting to discover his potential. Throughout the 2012/13 season he stepped up as one of the club's best players but his time at Arsenal wouldn't get better than the 21 goals scored in all competitions that campaign.

What was most memorable from that season was a hat-trick he scored in a 7-3 thumping of Newcastle when deployed as a striker. That will easily be his best performance in red and white but it summed up his career so far that he hasn't been able to replicate it.

During the same season there were concerns over whether Walcott would sign a new deal. However after months of speculation linking him with a move away he committed to the club on a £100,000 a week contract, making him the club's highest earner at the time.

It was at this period that Walcott experienced the best part of his career and perhaps he finally would have lived up to his potential if it wasn't for an injury that cut short his 2013/14 season.

Injury misfortune

In Walcott's twelve years with the club he had fourteen spells on the sidelines. Albeit some were extremely short, but it was his ACL injury in 2014 during an FA Cup tie with rivals Spurs that hampered him the most. He'd only just recently returned from an abdominal injury that kept him out for two months, before rupturing the anterior cruciate ligament in his left knee.

Despite already missing a portion of the season before his lengthy injury he'd still managed 5 goals in 13 Premier League games; a decent record for a wide player but he would go on to miss the rest of the season, the World Cup and much of the next campaign.

It's easy to think of what his career may have become if it wasn't for that ACL injury but it added to the frustrations his inconsistent personal performances would bring.

Phased out

Since his long spell out in 2014 Walcott hasn't appeared the same player we saw score 21 in 43 in 2012/13. A combination of injuries and eventually a change of system saw him cast out of the side.

In the last few seasons he has only been a bit part player, rather than a main stay. However what many don't remember is the fact he still scored 19 times last season, including ten league strikes; a record that has gone hugely under the radar.

It was his second best year for goals scored in a season and despite some average displays in cup competitions in 2017/18 was quite unfortunate to not get in the team ahead of the likes of Alex Iwobi.

Ultimately Walcott became a player who couldn't be trusted to deliver on a consistent basis. He scored some important goals for the club and in big games too but his inability to perform over a whole season and only in patches was hugely disappointing for a player who promised so much as a teenager.

Walcott walks out of Arsenal just three games short of 400 appearances for the club. In that time he scored 108 goals and was a part of three FA Cup winning sides.

On his day Walcott is an incredibly exciting player to watch but regrettably he will go down as one of the most underappreciated men to play for Arsenal, rather than as the star he was tipped to become all those years ago.