Despite still performing at the highest level at 34 years of age, Kroos will retire once Germany's current Euro 2024 campaign comes to its conclusion, meaning that he has already played his last game for Los Blancos.
Kroos remained a mainstay of Carlo Ancelotti's midfield last season, where he provided one goal and 10 assists from 48 matches en route to a La Liga, Champions League and Supercopa de Espana treble.
The 34-year-old ended the campaign with a sixth Champions League winners' medal around his neck, and he has started every game for Germany at their home Euros so far, including Saturday's 2-0 last-16 win over Denmark.
Ancelotti has left the door open for Kroos to make a sensational U-turn on his decision, but as things stand, there is nothing to suggest that the ex-Bayern Munich man will don the famous white strip again.
Real Madrid 'want Khephren Thuram' as Kroos replacement
Even with Kroos heading for the exit door, Ancelotti still has Federico Valverde, Dani Ceballos, Aurelien Tchouameni, Eduardo Camavinga and Luka Modric available to him; the latter is staying on for one more season.
Furthermore, in spite of claims that Manchester City could try to pull off a late hijack, Real Madrid are favourites to sign River Plate's Franco Mastantuono, although he will not arrive before the summer of 2025.
However, Sport claims that Los Blancos do intend to bolster their engine room with a direct replacement for Kroos this summer, and their eyes have been drawn to Nice's Khephren Thuram.
Son of former France defender Lilian Thuram and brother of Inter Milan striker Marcus Thuram, the 23-year-old has attracted the attention of some big names across Europe during his time at the Allianz Riviera.
Thuram has contributed nine goals and 12 assists from 167 games for Nice, but he is only under contract for another 12 months and will likely have to be sold this summer if Les Aiglons do not wish to let him leave for free.
Nice coincidentally did not pay a penny to sign the midfielder from Monaco's academy five years ago, and they would apparently be looking for around €15m (£12.7m) to €20m (£17m) to part ways with him this summer.
Who are Real Madrid's main contenders to sign Thuram?
Nice's relatively modest asking price - not a huge surprise given Thuram's contract situation - could alert a few more clubs to his availability, and both Liverpool and Juventus have been linked.
However, the Reds are not believed to be making a serious play for the Frenchman's signature at this time, as Arne Slot is also after a new centre-back and winger for the 2024-25 season.
Meanwhile, Juventus are working to close a deal with Aston Villa for the transfer of Douglas Luiz, so there is seemingly nothing standing in Real Madrid's way of moving for Thuram at this time.