Speaking to Sky Germany, Matthaus explained that Schlotterbeck simply wants to keep future possibilities open. Matthaus suggested that elite players naturally keep an eye on opportunities with Europe’s biggest clubs, and that such clauses are increasingly common in modern contracts.
"It was always about him wanting to take the next step," he said. "On the other hand, he's also committed to Borussia Dortmund. But if Real Madrid comes calling, you want to keep a door open, at least a small crack you can walk through.
"If fans now say, 'Oh, then he's not fully committed anymore' – that's not true. His heart will be in Dortmund. But he wants to keep that door open. If he can wait for another offer after a good World Cup, from which Germany would naturally also benefit, then that's the case with [Dayot] Upamecano, with [Jamal] Musiala, it's the case with all players – for some a little earlier, for others a little later. And if he has that option, he should be allowed to use it to his advantage, to perhaps get the chance to play for Real Madrid, for example. That's perhaps a dream come true, and even bigger than Borussia Dortmund."