Real Madrid are set to intensify their efforts to sign Nico Schlotterbeck from Borussia Dortmund after suffering a major blow in their pursuit of Dayot Upamecano. The Bayern Munich defender was identified as the club's primary target but is now on the verge of signing a new deal in Bavaria, forcing Los Blancos to pivot towards the German international who could cost upwards of €50 million.Real Madrid’s transfer strategy for the upcoming summer window has undergone a significant forced revision following developments in Germany. The Spanish giants had reportedly identified Bayern centre-back Upamecano as their priority defensive target. The appeal of the French international was twofold: his proven quality at the highest level of the Champions League and, crucially, his contractual situation.Upamecano was initially viewed as the "dream candidate" by the Madrid board because his contract was set to expire, making him available on a free transfer - a market strategy Los Blancos have exploited successfully in recent years with the likes of Antonio Rudiger, David Alaba and Kylian Mbappe. However, reports now indicate that the defender is on the verge of extending his stay at the Allianz Arena, effectively ending Madrid's hopes of landing him for free.With Upamecano likely off the table and the club reportedly cooling their interest in Liverpool defender Ibrahima Konate, the European champions have been forced to look further down their shortlist. That search has landed firmly on Borussia Dortmund’s Schlotterbeck.According to a report from Bild, a move for Schlotterbeck to the Spanish capital is becoming "increasingly likely" as Madrid step up their efforts to secure his signature.Unlike Upamecano, Schlotterbeck will not be available on a free transfer. The 26-year-old’s current deal at Signal Iduna Park runs until the summer of 2027. This contractual stability places Dortmund in a stronger negotiating position, with reports suggesting that the Bundesliga side would demand a fee of at least €50m (£43m), though some reports put the asking price in the region of €70m (£58m) to part ways with their defensive leader.Despite the cost, Schlotterbeck is now the top name on Madrid's internal "wish list" for the centre-back position. The player himself is reportedly open to the idea of a move to the Santiago Bernabeu, although he has yet to make a definitive final decision regarding his future. Dortmund, meanwhile, would rather sell him to a foreign club than see him join Bayern.Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!The uncertainty surrounding Schlotterbeck has become the dominant topic at Borussia Dortmund. The club has been attempting to extend the German international’s contract for months, but those efforts have so far failed to yield a signature.Dortmund’s hierarchy is keen to avoid a saga that drags on into the summer transfer window. Sebastian Kehl, the club’s sporting director, recently addressed the situation in an interview, making it clear that a decision is expected sooner rather than later."We have been in good and trusting discussions for some time and there will be a decision in due course," Kehl stated. "That will certainly not be the case only sometime in the summer, everyone involved agrees on that."Add GOAL.com as a preferred source on Google to see more of our reportingReal Madrid’s pursuit of a high-profile central defender comes amidst a period of instability in their backline. The club has navigated a series of long-term injuries to key personnel such as Eder Militao and David Alaba over the past 18 months, stretching their squad depth to the limit.While Antonio Rudiger has been a colossus in defence, his contract expires this summer and the need for an eventual successor has become a priority for the board. The profile of Schlotterbeck fits the bill: a left-footed, ball-playing centre-back with experience in high-pressure environments.However, the shift from a free transfer target in Upamecano to a massive investment in Schlotterbeck represents a significant change in financial planning for the summer. It remains to be seen whether Florentino Perez will sanction such a heavy outlay for a defender, or if the player’s hesitation to renew with Dortmund will open the door for a negotiation on the fee.For now, the ball is in Schlotterbeck’s court. With Dortmund pressing for an answer and Real Madrid watching closely, the coming weeks are likely to determine whether the German defender becomes the latest star to trade the Bundesliga for La Liga.