When German international Musiala sustained a fracture of the fibula (a bone in the lower leg) associated with an ankle dislocation in a hard collision with PSG goalkeeper Gianluigi Donnarumma at the Club World Cup, Bayern Munich lost the key to their otherwise well-oiled engine room at the very heart of their midfield.
Since making his debut five years ago, Musiala has proven his immense importance through consistent, game-changing performances, becoming Bayern Munich's youngest centurion, a key scorer for Germany, and an elite playmaker known for his dribbling, creativity and ability to provide the goods in decisive moments, solidifying his status as a future Ballon d'Or contender.
And with just six weeks to go before the start of the Bundesliga season, coach Vincent Kompany was ready to sound the alarm bells at Saberner Strasse as Bayern had no direct replacement available to fill in for their midfield star.
After spending 25 years with the club, making over 700 first-team appearances and winning more than 20 trophies, Thomas Muller was allowed to leave Bayern Munich at the end of the 2024/25 campaign.
At the same time, the 29-year-old Leroy Sane had chosen not to accept a new contract offer from the German record champions and surprisingly opted to join Istanbul outfit Galatasaray on a three-year contract.
On top of that, Die Roten reportedly decided against spending a massive fee (potentially over €100m) on Florian Wirtz due to financial concerns, a desire to avoid shattering wage structures, and a strategic shift towards balancing big-money moves with player sales, ultimately losing him to Liverpool despite significant interest.
However, when desperation was about to set in among the Bayern management, Kompany ironically found Musiala's replacement in a place that Bayern had, for decades, been renowned for ignoring: the academy.
Bayern's reluctance to integrate academy players into the first team squad wasn't new to the public, but the discussion was reintroduced during the beginning of the Club World Cup when former Bayern defender and German international Marcus Babbel questioned Kompany’s refusal to make use of young talents.
Under-19 players only managed to get 110 minutes of game time in total with the first team at Bayern last season, and if you take a look at the total minutes other big clubs afforded to emerging youth talents and/or debutants, it shows a deep contrast. Liverpool had 975 minutes of play, while PSG had 966 and Real Madrid had 570, respectively.
With that background, it's ironic that it would take a serious injury to one of their absolute key players before the value of the academy actually dawned on Bayern as 17-year-old Karl emerged as one of the brightest young talents in German football to claim a regular place in the Bayern starting lineup.
Since the emergence of Muller in 2008, Bayern fans had not experienced a German academy graduate develop through their ranks and turn into a key player on the pitch. And with superb goals against Club Brugge and Borussia Monchengladbach in October, the prolific midfielder became Bayern's youngest goalscorer in the Champions League and the third-youngest in the Bundesliga.
Less than a year after Karl was playing under-19s football, many football experts and fans are now calling for his inclusion in Germany's 2026 World Cup squad; his rise to fame has been truly remarkable.
In the latest Champions League fixture against Sporting CP, where Kompany felt he could have done better even though he was voted Man of the Match by UEFA, the Bayern coach said: "He always remains incredibly dangerous. If you can be dangerous four or five times during a match at this age without playing your best game - that's impressive."
But with Musiala on the verge of making a comeback, the excitement over Karl's promising performances has been overshadowed by one big question: how do you put him back on the bench after his performances?' How do you maintain his progress and motivation to keep pushing without alienating Musiala, Germany's next Matthaus, in the process?
Musiala, as well as Karl, operates as a midfielder, but can also be used on the wing, creating a selection dilemma for coach Vincent Kompany.
Musiala no doubt prefers to play centrally as the primary attacking midfielder, but that poses a problem as Karl also frequently delivers his best football as a playmaker.
With Musiala on the verge of returning to full fitness, is Karl going to pay the price for his comeback? At a club like Bayern, where results and titles are always the top priority, it seems unlikely that Kompany won't prioritise Musiala.
For Bayern Munich CEO Jan-Christian Dreesen, the discussion of Musiala or Karl shows that Bayern is headed in the right direction.
“I think this discussion is quite astonishing. Because I remember very well when we regularly discussed the thin squad in late summer. I said back then that a thin squad offers great opportunities for talented players. We’ve seen that now. Lennart Karl has done an outstanding job.
"Competition always helps to improve overall performance, and I’m sure the coach will find the right solutions,” Dreesen said to German media. “It takes something special to keep motivating yourself for so long. We are very happy that Jamal is now back training with the team.”
Regardless of how Kompany chooses to solve the puzzle between Musiala and Karl, the emergence of Karl and the success he has enjoyed in Munich may indicate the beginning of a new approach at Bayern, where more youngsters will be handed a chance to shine.
Kompany selected no less than seven youngsters (Cassiano Kiala, David Daiber, Deniz Ofli, Felipe Chavez, Javier Fernandez Gonzalez, Wisdom Mike, and Karl for the last game of the year against Heidenheim, which might signal that Bayern will revise their strategy around their academy players.