This article is part of Football FanCast's In Numbers series, which takes a statistical look at performances, season-long form and reported transfer targets...

Jose Mourinho currently has some issues in his backline.

Of course, the fact that his team have conceded a total of eight goals in four games tells a big part of that story, but it's not the entirety of the problem he could face.

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Both of his central defenders, Toby Alderweireld and Jan Vertonghen, have still not signed contract extensions and their current deals expire in the summer of 2020.

At the very moment, it is still quite possible that Spurs will lose both of them either on a discount or for free, unless Mourinho can work his magic and turn a couple of heads in the process.

But this situation could've been avoided long ago, back when Mauricio Pochettino was in charge of the club. As The Sun claimed in June earlier this year, Spurs were ready to fork out £40m to land Nathan Ake from Bournemouth, while Sky Sports reported their interest in October 2018.

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It seems that Pochettino was very much aware of the defensive situation at the club and he wanted to act on it.

Of course, Spurs failed in their conquest and are now in a tricky situation because of it. Looking at Ake, however, he truly looks like someone who could've helped them fix some of their issues and also represent a bet for the future.

The 24-year-old has already played a total of 15 games in the Premier League for Bournemouth this season, even scoring and assisting once in the process.

But he also averaged 1.3 tackles and 1.5 interceptions per game for his team, along with an impressive 4.4 clearances. Not to mention that he was only dribbled past 0.2 times per game, which further solidifies how instrumental he is in that backline.

Even when he's on the ball, Ake is a fairly safe option in possession with 89.7% passing accuracy and 50.5 passes per game.

By all means, £40m doesn't look like a price too big to pay for a reliable defender who's bound to be around for a number of years.

Reigniting that interest could very well be a wise move for Mourinho if he's intent on fixing his team's defensive woes.

Meanwhile, Roma could snatch one of Chelsea's big transfer targets that could help them patch up their squad...