Replacing Christian Eriksen or Dele Alli would be scary proposition for Spurs
Tottenham have repeatedly stated their top stars are not for sale and Spurs have done a tremendous job of keeping their core together. But it's not going to stop fans from talking about their best players and their futures, as demand and pressure from other clubs will never stop. So let's have a hypothetical debate.
It's the summer of 2018 and FA Cup winners Spurs have a decision to make. Barcelona have offered a world-record fee for Christian Eriksen, who finished with the most assists at the World Cup, but Real Madrid have done the same for England's Dele Alli. Finances at Tottenham are tight after finishing the new stadium and Ballon d'Or winner Harry Kane needs another new contract.
Daniel Levy and Mauricio Pochettino reluctantly agree to sell one of the midfielders and the chairman solemnly promises his manager to reinvest at least half the fee in a replacement. So which one should Spurs sell?
Most Spurs fans would grudgingly opt for Alli but, on paper at least, he is just as valuable as Eriksen. The England international directly contributed to two more league goals last season -- 25 to Eriksen's 23 -- and he is four years younger. Though Eriksen is the finished article, Alli, by his own admission, is still learning and the 21-year-old also boasts that indefinable air of "marketability", which is so valuable to football clubs.
Of the two, Eriksen is clearly the harder to replace within the current squad. The deadpan Dane is the lifeblood of Tottenham's creativity, setting the tempo and making them tick. Without Eriksen, Spurs would be lost but there is nobody even close to an alternative in Pochettino's squad. It is Spurs' biggest weakness and explains why the manager was interested in signing Barcelona's Andre Gomes in the summer.
Alli, by contrast, is now a final-third player and the best goal-scoring midfielder in the Premier League. He has a rare ability to find space in the box and finish, and he is developing into the ultimate right-place-right-time player, who frequently makes no contributions except the most important ones.
Because of this, he is more easily replaced than Eriksen in one-off games, as Spurs proved in the landmark 3-1 win against Borussia Dortmund, when Alli's replacement Son Heung-Min opened the scoring. The South Korean is expected to deputise for the suspended Alli again in this month's match at Real Madrid and it should cause minimal disruption to Spurs' style and approach at the Santiago Bernabeu.
If Pochettino was forced to choose which of the two he would rather lose to injury for the next three months, he would surely pick Alli.
Though replacing Eriksen from outside the squad would be a daunting task, it would be even harder for Tottenham to find someone like Alli and to replace his goals long-term -- even with a £75 million hole burning in Levy's pocket.
Eriksen is a unique talent but Europe is awash with brilliant playmakers, and most of Spurs' top-six rivals have one. Manchester City trio Kevin de Bruyne, David Silva and Bernardo Silva, Liverpool's Philippe Coutinho, Arsenal pair Mesut Ozil and Santi Cazorla, Manchester United's Juan Mata and even Everton record-signing Gylfi Sigurdsson are all tempo-setting No. 10s, who are positionally versatile and can score goals as well as create them. They may not be all that similar to Eriksen but they contribute in similar measure.
Spurs would not be able to replace Eriksen with any of them but there is no shortage of young options with high potential, like Ante Coric or Dani Ceballos, or they could trust Pochettino to take someone like Manuel Lanzini up a couple of levels.
However, though Eriksen makes everyone around him better, Alli is a difference-maker capable of moments of genius and decisive interventions out of nothing. There are much fewer players like him around and none of Spurs' rivals have a No. 10 who will score 20 league goals a season -- as Alli surely will this year. It is so difficult to buy guaranteed goals, particularly from a deeper position, as Spurs have found in recent years and that makes Alli a precious commodity.
Back in the here and now, Spurs are lucky to have both and there is no suggestion that they will have to sell either next summer or beyond. Their different styles and strengths are perfect for Pochettino but they make it hard to say which player Spurs could least afford to lose.
Dan is ESPN FC's Tottenham correspondent. Follow him on Twitter: @Dan_KP.