The summer transfer window hasn't even officially opened yet, but Toni Kroos' future already looks likely to be one of the hottest topics on discussion as Real Madrid and Barcelona contend for his signature.

According to Oscar Mendez of Spanish newspaper Marca, the La Liga giants have each sent representatives to Brazil in hopes of beating their rivals to the midfielder's signature.

Kroos' Bayern Munich contract has just a year remaining and it doesn't appear likely he will be extending his deal at the Allianz Arena.

The 24-year-old is currently at the 2014 World Cup and spoke on the matter of his potential exit from the Bundesliga giants after triumphing 4-0 over Portugal in his nation's tournament opener, per The Independent's Jack de Menezes:

There's nothing new to report. With respect to the time before the World Cup, nothing at all has changed. If anything does happen, then you will all find out. Congratulations to Philipp and Thomas for their decisions and extensions.

Kroos' current situation is an odd one given that he is among Germany's most valued up-and-coming talents, graduating from Bayern's youth setup before excelling in their senior ranks in recent years.

One can only imagine that finances are playing a big hand in his decision to leave, with money-making opportunities more common outside of his native Germany. The Premier League is a particularly lucrative destination for the world's stars.

The playmaker has maintained his impressive 2013-14 standards at the World Cup, and Squawka shows that despite Die Mannschaft's slightly disappointing 2-2 draw against Ghana, he stood as one of the fixture's more impressive figures:

Carlo Ancelotti's midfield core is an area of some contention at present. Sami Khedira is only just coming back into the squad after having surgery on an anterior cruciate ligament injury, while Casemiro and Asier Illarramendi are both on the fringes and could potentially be farmed out on loan, says Mendez.

Barcelona, meanwhile, have just acquired the services of Ivan Rakitic after selling Cesc Fabregas to Chelsea.

However, Xavi is expected to leave a sizeable void in the midfield, with Rhys Turrell of the Daily Star reporting that the veteran—who just retired from Spanish international duty—is moving to Qatar club Al Arabi.

Each club has reason to be seeking a player of Kroos' skill set. However, it's possible that Bayern may yet decide to resist any offers, hold onto his talents and instead allow him to leave for free next summer.

Usually, one would say the money involved would be too tempting to turn down. However, if there is an elite level of club that can afford to be stubborn in such circumstances, Bayern are certainly amongst it.