For three seasons now, Tottenham Hotspur fans have considered themselves very lucky to have a gifted centre back in Jan Vertonghen.
A defender with pace and finesse, which allowed him to play in defensive midfield or at left back earlier in his career, the Belgian was one of Tottenham's most highly rated assets following a fantastic opening season under Andre Villas-Boas during which he showed fantastic potential.
Following two more seasons spent toiling at White Hart Lane, the summer of 2015 arrived and Vertonghen's progress was deemed to have stalled. Fantastic performances, in which he looked strong, menacing and even creative, came just as often as performances in which he looked overawed and anemic.
Performances against the big sides during the 2013/14 season, during which Spurs were hammered twice by Liverpool (0-5 and 4-0) and twice by eventual champions Manchester City (1-5 and 6-0), alongside his performance against Stoke towards the back end of the 2014/15 season, in which Spurs were thrashed 3-0 away from home, seem to provide a body of evidence that Vertonghen had been worked out by forwards since his excellent break through season in English football.
Revolving door of defensive partners
A series of central defensive partners came and went. Michael Dawson was considered too slow for top fight football. Younes Kaboul and Federico Fazio too clumsy, Vlad Chiriches neither a good enough ball player nor a big enough physical presence to accompany the languid Vertonghen.
Eric Dier looked the most promising alongside the Belgian international, yet his career has taken a different turn at Tottenham, seemingly to the benefit of both him and Vertonghen, as he has moved into a defensive midfield role in which he shields the defense.
Re-united with Ajax teammate
Defensive troubles undermined Spurs' new found attacking prowess last term, and hence it was decided defensive recruitment was a priority. So came Toby Alderweireld to White Hart Lane, following an impressive loan spell at Southampton. This has proven to be a turning point for Tottenham this season, and has seen them march to fourth place in the league at Christmas, with almost half of the season having been played out.
First of all, Alderweireld has represented a massive improvement, in terms of quality, in comparison to Vertonghen's aforementioned previous partners. His physical presence allows him to outmuscle even the strongest opposing forwards, whilst his aerial abilities annd pace give him the confidence to dispossess the opposition at the crucial moment.
Above all, his skills give him confidence in his footballing abilities, and this makes him less prone to individual blunders, which ultimately led to the downfall of a number of predecessors. While the sight of a nervy Vlad Chiriches backpass may have induced sleepless nights for many a Spurs fan, no such worries exist with Alderweireld. In fact, his ability to play out of defence is a massive positive, as seen when he set up Dele Alli's goal against West Bromwich Albion with a 45 yard through ball, which Alli converted with a first time volley.
He has claimed several man of the match awards since joining Spurs, and has been rated amongst the best central defenders in the league this season.
Influence on Vertonghen
Although, Alderweireld's personal impact has been enormous in improving Spurs defensively, the influence upon the aforementioned Vertonghen has been as positive. Prior to his arrival, there was talk of him being a prefered target due to his prior experience playing alongside Vertonghen for Ajax and Belgium.
While scepticism existed before the beginning of the season, the Belgium duo have indeed formed a partnership which is finally getting the best out of Vertonghen.
Alongside Alderweireld he seems far less inhibited by the possibility of having to cover for a defensive mishap caused by his partner. Consequently, he has looked much more than just the elegant ball player which he did in the previous three years.
Fantastic performance against former employers
The epitomy of this was during last Saturday's victory for Spurs against Southampton. Between them, Vertonghen and Alderweireld managed to steady the ship as Spurs started slowly. Southampton prioritised feeding the lone striker Graziano Pelle with countless crosses, and this proved hard graft for the Belgian pairing, considerring that accomplices Sadio Mane and Dusan Tadic were always lurking not far off the towering Italian.
Spurs held strong though, and thanks also to a much stronger midfield unit, Spurs kept a clean sheet and maintain a very impressive goal difference in the league. Alderweireld made one interception, two blocks and eight clearances, whilst also winning two out of his three aerial duels - a very fine display and one which Spurs fans have come to expect of the man who was facing his former club.
Vertonghen's performance was even more impressive however, making three tackles, three blocks and three interceptions as he foiled Southampton's attackers on numerous occasions. This is testament to the forward strides Vertonghen has made personally, and the impact on Spurs' performances now that they have a settled central defensive partnership, which is up their with the tightest in the division.