Real Madrid have paid a heavy price for failing to replace Toni Kroos following his retirement in 2024, but then doing so was always going to be a tough task. For starters, the ex-Germany international ranks as one of the finest deep-lying playmakers of the modern era.An heir to Kroos' throne could now be emerging in his homeland, and Madrid are already showing an interest. Angelo Stiller has been a shining light for Stuttgart over the past couple of campaigns, and as he approaches his 25th birthday, now looks set to make a big-money move in the summer transfer window.But who is Stiller, and what makes him so special? We've got everything you need to know about the latest member of Hidden Gems FC...Stiller was born into a Bayern-mad family in Munich. One would have thought, then, that when his hometown club first came calling, he would have immediately jumped at the chance to join the Bavarian giants.However, the eight-year-old Stiller made Bayern wait. He spent another season playing with his friends for local team Milbertshofen before eventually signing for the six-time champions of Europe in 2010. Stiller wasted little time progressing through the Bayern youth team ranks thereafter and was playing for the Under-19s while still only 17.To say that Sebastian Hoeness has been a big influence on Stiller's career would be putting it very mildly indeed. It was the former Hertha Berlin attacking midfielder who called a teenage Stiller up to the Bayern reserves in 2019, and his impressive performances in Germany's third tier led to a first-team debut under Hansi Flick in October of the following year.However, that proved to be one of only three appearances he would make for the Bavarians, totalling 64 minutes, and the failure to keep hold of Stiller still wrangles the German giants to this day."Something like what happened to Angelo Stiller must never happen to us again," Bayern's director of football development and campus manager, Jochen Sauer, insists. "Angelo went through all the youth teams from the campus to the third division and then left on a free transfer to Hoffenheim. We should have reaped the rewards of our training programme better."Hoeness' presence at Hoffenheim played a key part in Stiller's decision to move to the PreZero Arena when his Bayern contract expired at the end of the 2020-21 campaign. And so, when Hoeness left for Stuttgart, it wasn't in the least bit surprising to see the pair reunited again in the summer of 2023."It's definitely something special when a coach follows your career for so long and you get to play under him," Stiller told the Bundesliga's official website. "I think we both see football the same way. I believe we both want to play the same kind of football, both offensively and defensively, and I think that it is important that we have that trust."Hoeness' departure from Hoffenheim in the summer of 2022 was unsurprisingly a serious setback for Stiller. He still featured 20 times during the following campaign, but he started only six times. Consequently, Stiller wasn't at all happy with how his career was progressing. He felt as if he were stagnating, which is why he jumped at the opportunity to be reunited with his mentor at the MHPArena.Stuttgart paid just €5.5 million to sign Stiller in the summer of 2023 and it quickly proved a sensational bit of business, with the defensive midfielder helping the club to a shock second-placed finish  the 2023-2024 Bundesliga before they went onto win the DFB-Pokal last term.Stiller also broke into the Germany squad after Kroos' post-Euro 2024 retirement from football and has earned five caps for his country, though Julian Nagelsmann has hinted that he still needs to see more from the midfielder before he can be confident in selecting him for the 2026 World Cup.Add GOAL.com as a preferred source on Google to see more of our reportingStiller is not your typical ball-winning defensive midfielder. He's a gifted, multi-talented playmaker who has drawn comparisons to not only Kroos but another of his esteemed compatriots in Joshua Kimmich, due to his ability to read the game and pick a pass.Indeed, he's one of the Bundesliga's most creative players, as underlined by his tally of 17 assists since the start of the 2023-24 campaign, while he's also chipped in with six goals across all competitions.What Hoeness really loves about Stiller, though, is his maturity, which he says has stood out since he was playing under-age football at Bayern. Consequently, he has never had any doubts about his protege's world-class potential, and was even pushing for him to be called up by Germany for Euro 2024 while Kroos was still around."He is always able to adapt to a higher level," Hoeness said. "He is able to dictate a game - and that's because he understands the game. He knows just how many touches he needs in a particular situation - and that is rarely more than two, sometimes just one."Stiller freely admits that his defensive game wasn't as good as it should have been during the early part of his professional career, and it's something that he's still working on. Nonetheless, he feels he's getting better and better at anticipating danger, timing tackles and winning duels."That's a good feeling, one that I didn't have before," he told Bundesliga.com. "It was drilled into me that football isn't just about having the ball; it has to hurt sometimes too."Stiller is likely to have a big decision to make this summer, with interest in his services intensifying. Liverpool and Manchester United have previously been linked with moves for him, but is the Madrid rumours that just won't go away given Los Blancos' struggles over the past 18 months.The Germany international has a €40 million (£34.5m/£47m) release clause in his contract that comes into effect this summer, meaning a rush to secure his signature could well be on the cards as soon as the campaign wraps up. Stiller, though, likely won't be rushed into a transfer; he bided his time as an eight-year-old before joining Bayern, and he'll probably do likewise before deciding his next move.