Upon celebrating his 30^th Birthday today, Mousa Dembele can rightfully lay claim to being arguably the most underrated player in the Premier League, if not European football.

Indeed, when you think of the Tottenham Hotspur side that have defied expectations to launch two consecutive Premier League title bids, more illustrious names come to mind first - Harry Kane, Dele Alli, Christian Eriksen, Toby Alderweireld and even goalkeeper Hugo Lloris.

But Tottenham are always a different team when the Belgium international is in the side; in fact, throughout his five seasons at White Hart Lane, Spurs’ win rate improves by 7% when Dembele’s in the starting line-up - the kind of marginal difference that can separate trophy-winners from also-rans, although the midfielder’s Spurs career thus far has been fruitless in that regard.

In fairness, Dembele has received more recognition in recent seasons as Spurs have progressed from Champions League qualification hopefuls into title chasers under Mauricio Pochettino - a manager who has seemingly got the best out of a player who often frustrated during his first few campaigns at White Hart Lane.

But the statistics suggest that’s as much about perception, not only amongst Spurs fans but also the wider Premier League, as the five-year transition of Dembele’s game.

2013/14 and 2014/15 were very much campaigns in the wilderness for Dembele and to a lesser extent, Tottenham in general. That’s perhaps when Dembele received the most criticism, not only for his form but also his style of play.

When Spurs purchased him from Fulham, the Belgian was very much part of the attack, a support striker playing just behind Andrew Johnson, but Andre Villas-Boas and later Tim Sherwood both utilised him as a central midfielder, on some occasions even the deepest-lying.

Accordingly, when Dembele completed his third Spurs season with just three Premier League goals to his name, one per term, bemused eyebrows inevitably raised that little bit more. Even during bouts of good form, the same criticism always arose; quite simply, he didn't score enough goals - especially for a player who once occupied the space behind the central striker.

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Yet, in the two campaigns since Dembele hasn’t resoundingly improved, bumping up his season average of one Premier League goal to two, but he’s now held in much higher esteem - even if the importance of what he provides for Tottenham still slips ever so slightly under the radar.

Likewise, although there’s an obvious difference in terms of created chances per match, highlighting how Dembele has been utilised in increasingly deeper roles, the 67-cap midfielder’s outputs over the last two campaigns are largely in line with his first season at the club - a similar number of passes per match and an identical percentage of passes forward, alongside similar returns for tackles, interceptions and shots per match - and perhaps unexpectedly, an escalation in the number of dribbles.

Ironically, considering the question marks over his attacking contributions after first arriving at White Hart Lane, making himself more passive has slowly but surely won the naysayers over. That’s in part due to a higher level of performance in comparison to 2013/14 and 2014/15, but also how expectancy of not only Dembele but also all Premier League midfielders has steadily changed.

When Dembele first arrived at Tottenham, top-quality central midfielders were expected to score goals - a consequence of Frank Lampard, Steven Gerrard and Yaya Toure’s proficiency at Chelsea, Liverpool and Manchester City respectively. Perhaps that’s what Spurs coaches and fans thought they’d get out of Dembele, a cheaper alternative to those dynamic, swashbuckling midfield goalscorers.

But since the end of the 2013/14 season, the number of Premier League goals from midfield has waned, as has the number of midfield goalscorers and the number of midfield goals from distance.

In the last three years, for a variety of reasons, goalscoring midfielders have seemingly become that bit less important, the emphasis shifting out wide or in the case of last season, to the two forwards either side of the central striker in a 3-4-3 setup - something Pochettino adopted for large periods of 2016/17.

Instead, the primary task of central midfielders has become much more functional - simply, to exert control over their area of the pitch both with and without the ball. That’s exactly what Dembele does; his physicality helps keep it tight defensively, whilst also giving him the frame, when combined with his technical quality, to retain possession with a classy mix of skill and power.

His resulting importance to this Tottenham side, therefore, is impossible to overstate. He produced the best pass completion rate of an Spurs player last season, 92%, in a Lilyhites side that averaged the third-highest percentage of possession throughout the division - their 57.4% only beaten by Liverpool and Manchester City.

No doubt, however, Dembele is still a rather unique footballer; a one-time support striker who is now at his best as a deep-lying playmaker, preferably alongside another powerful presence like Eric Dier or Victor Wanyama. Not many players have successfully made that transition and it's certainly taken time - just as it's taken time for Dembele's importance to Tottenham to truly shine through.

Turning 30 today, the inevitable question now is how long Dembele can actually go on for. But that change in roles may well be what extends his career far longer than if he was still considered a forward player.

Pace is no longer vital to his game in the same way and the Belgian's natural quality on the ball reeks of permanence. Still underappreciated in the grand scheme of the Premier League, that likely longevity may be what eventually earns Dembele the further recognition his qualities deserve.