The build-up to Arsenal’s 2-0 win over West Bromwich Albion on Monday night contained a curious subplot that has been discussed more than once before in Gunners circles; life after leaving the north London club.

Kieran Gibbs’ impact may have been minimal during his final few seasons at the Emirates Stadium and indeed during a ninety minutes that saw Arsenal resist first-half pressure to secure a routine win over a side who’ve managed to score on their patch just eight times throughout the Premier League era.

But the England international’s declarations upon swapping his boyhood club for the Hawthorns at the end of the summer transfer window certainly created a talking point.

"(Tony Pulis is) different to what I've had before and I feel he can develop me in certain areas I maybe need to work on. He can help me progress."

While Gibbs insinuated Tony Pulis will improve the defensive side of his game - a more than acceptable insinuation considering how well-drilled the Welshman’s backlines always are - Arsene Wenger retorted by questioning the number of players who’ve actually enjoyed a higher level of performance after absconding north London.

"Once someone takes the decision to leave I wish them well and focus on my squad, but just look at the performances of the players who left us and then come back to me about it.

"Learning is an attitude in life. It doesn’t depend on your geographical status, but more of the attitude in your brain. Are you ready to question yourself every day to see if you can improve?"

There are certainly many players who have gone on to greater success after leaving Arsenal in terms of silverware; Robin van Persie won his first Premier League title upon trading the Gunners for Manchester United, Kolo Toure and Samir Nasri jumped ship to Manchester City to fill their trophy cabinets and since departing in 2011, Cesc Fabregas has gone on to claim a whole haul of honours with Barcelona, Chelsea and Spain.

But in terms of actual performances, Wenger’s argument does largely ring true. Van Persie only enjoyed one great season at Old Trafford; Fabregas never held down a starting XI role at Barcelona, except for a prolonged spell as their emergency false nine, and isn’t an automatic pick at Stamford Bridge; Nasri has never managed more than the ten goals he scored for Arsenal during 2010/11 and his career is now in the wilderness, while Toure was largely out of the picture after just 18 months at the Etihad Stadium.

The classic case study, though, is a former Arsenal man whose own boyhood club BATE Borisov will take on Wenger’s side later this week - Alexander Hleb. The immediate assumption upon leaving Arsenal for Barcelona, all the more tellingly two years after they’d lost to the Catalans in the Champions League final, is that your career’s on the verge of reaching its pinnacle.

But the regard the Belarusian was held in during summer 2008 proved not to be a prophecy of greater things ahead, rather, the peak that Hleb sharply, steadily and relentlessly slid down from. Three seasons at Arsenal would represent his greatest years; four years on the books at the Nou Camp would represent easily his worst, filled with injury problems, underwhelming loan spells and the eventual admission that he should have never quit the Premier League side.

It’s easy to forget that Hleb was an incredibly talented player, the closest thing Arsenal had to Dennis Bergkamp following the Dutchman’s retirement and arguably until they signed Mesut Ozil in summer 2013. An attacking midfielder of great vision, agility and dribbling ability, he occupied those spaces between the midfield the defence that have become synonymous with Arsenal playmakers down the years - just eight goals and twelve assists in 108 league appearances doesn’t tell the true story of how instrumental Hleb was during his three seasons with the Gunners.

Yet, the 77-cap international probably wasn’t at the standard we grew to expect from Barcelona during his time there, which perhaps explains why Arsenal were so open to parting with him for just £15million - a decent if not exactly resounding sum just over a decade ago. Arsenal reinvested that money in Aaron Ramsey and Nasri during the same summer, two attacking midfielders most fans would argue the club has got far more out of than Hleb’s three productive years.

In any case, Hleb’s four seasons at the Nou Camp were far from enjoyable. His arrival coincided with the appointment of Pep Guardiola, taking place just one month after during the same summer, and judging on how sparingly he featured during his first and only season in the first team, making just seven starts in La Liga, he was never the Spaniard’s signing. The right wing role he took at Arsenal was adopted by a certain Lionel Messi, who finished the season with 38 goals, while even a then-17-year-old Bojan made more appearances across all competitions.

Perhaps Hleb happened to join Barcelona at the worst possible time; after all, Guardiola guided the club to unprecedented success, using players like Messi, Bojan and Pedro who he’d already worked with at Barcelona B. But it wasn’t a matter of Hleb not being given chances - he picked up 1685 minutes across all competitions in 2008/09 - more simply, that he was no better than any of the other midfield and attacking options at Guardiola’s disposal. He just wasn’t good enough.

"Of course I regret leaving Arsenal. I was playing every week for one of the most exciting sides in Europe, a team which was always in the top four in the Premier League and were Champions League contenders.

"Also, I was being guided by one of the best coaches in the world in Arsène Wenger. I owe him a great deal. I developed a better all-round game under him and I became more robust physically, learnt to look up more and play better passes and generally improved greatly as a team player.

"No player ever gets worse under Wenger. For me, leaving Arsenal was not a good move."

By the end of his debut season at the Nou Camp, that had become painfully clear. Consequentially, the next three years of Hleb’s career consisted of loan spells that epitomised his sudden fall from grace - a goalless stint at Stuttgart, the club Arsenal had originally acquired his services from, a short-lived stay in the Premier League at Birmingham, where he rarely looked like the same player we saw at Arsenal, and a four-game spell with Wolfsburg.

After that, Hleb’s Barcelona contract was terminated and by way of Krylia Sovetov Samara, he soon found himself back at the place where his senior career had started - BATE Borisov. Four years on from a move that theoretically placed the world at his feet, Hleb had returned to square one. The £15million ladder to Champions League glory and superstardom turned out to be a snake, one that took him full circle.

Now 36 years of age, Hleb isn’t encroaching retirement as an Arsenal favourite or a Barcelona idol. He may be a hipster’s choice in some corners of the Arsenal fan base, but he’s not remembered in the same fondness as someone like Mikel Arteta, or even the hatred inspired by someone like Samir Nasri. He’s a three-year footnote, one who doesn’t inspire huge emotions either way; in fact, his ultimate purpose in the context of the north London club at this point is quite simply a reminder that the grass isn’t always greener, whether it’s Tony Pulis or Barcelona that come calling.

Gibbs may feel West Brom represented the right move for this uncertain stage of his career and in truth, it's hard to argue against that considering the last few seasons. But the fact of the matter is that very few players become better footballers after leaving the Emirates. For most, even if they manage to gloss over it with silverware, quitting north London represents the first steps of the decline.