The Bundesliga's top teams have just started a demanding set of fixtures. Player management, squad depth and a little luck will determine the season just as much as pure skill and mentality.
Robert Lewandowski doesn't miss football matches. The 32-year-old is the ultimate competitor. He rarely gets injured and he almost never misses a Bundesliga game.
The Bayern striker's absence during the German Cup on Thursday therefore spoke volumes. A slight ankle niggle was cited, but this was injury management. For the first time in his German career outside suspension or injury, Lewandowski wasn't selected for duty.
It's a sign of the times as the Bundesliga's top teams embark on a brutal schedule. COVID-19 has forced football associations, both domestic and international, to pack as many games together as they can fit.
While schedule management is a factor in the outcome of every season, this season it looks set to play a major role.
Bayern put out a second-string team against Düren in the German Cup. Two days later for the 4-1 win over Bielefeld, Hansi Flick made nine changes, bringing back the first team.
"We want to play our football and implement our ideas fully," Flick said beforehand. "That only works with 100 percent. If a player can't give 100 percent, then another will play."
It is clear that trust in fringe players will be an even bigger issue this season than normal.
Added COVID-19 risk
Dortmund welcomed back 10 players from international duty yet had no choice but to start five of them against Hoffenheim.
Erling Haaland, Raphael Guerreiro, Jude Bellingham, and Thomas Delaney were at first rested but then came off the bench to help secure a hard-fought 1-0 victory. Haaland's contribution in particular was vital, highlighting just how important Lucien Favre's management of the 20-year-old will be this season.
A serious injury to the young Norwegian and Dortmund's season might well unravel.
Meanwhile, Dortmund defender Manuel Akanji and Hoffenheim's Kasim Adams and Andrej Kramaric were unavailable for selection due to positive COVID-19 tests while on international duty.
"I think we have to be careful. It's dangerous, There will be more cases, it's not good to travel," Favre admitted after the Hoffenheim match.
Hoffenheim sporting director Alexander Rosen cut an even more frustrated figure, saying that in an emergency it was time to think hard about not letting his players travel.
With coronavirus infection rates rising across Europe, the Champions League group stage just days away from starting and the next international break currently planned for November, managing player health will be a pivotal factor.
Fringe and youth players are likely to get more opportunities than ever before this season and success will depend on which squad has the best and most viable options.
Bayern's business in the transfer window stands them in good stead, with sporting director Hasan Salihamidzic securing the late signings of Eric Maxim Choupo-Moting, Douglas Costa, Bouna Sarr, and Marc Roca.
None of them were signed as first-team regulars, but they all boast experience - only Roca is aged under 28. With all four starting in Bayern's 3-0 German Cup win, their importance is already obvious.
The chasing pack in the Bundesliga have not had the financial clout of Bayern Munich for some time, and the coronavirus has seen many tighten their purse strings out of pure necessity.
Leipzig, Dortmund, or Gladbach all made signings, but the true depth of their squad in such an unusual season may prove decisive throughout the season.
Just the beginning
When the Champions League returns on Tuesday, the Bundesliga representatives will begin a relentless barrage of games all the way up until Christmas.
Six games within 26 days domestically will be followed by the aforementioned November international break, which will see many players involved in another three matches in seven days. Just before that on November 7, Dortmund and Bayern play one another in the Bundesliga.
From then on, the schedule is even more daunting. Ten matches within 32 days will put an extraordinary amount of strain on even the biggest of squads.
How the respective coaches manage their squads will test their judgement, maturity, and man-management more than ever before.
More injuries, positive COVID-19 tests, and mental burnout seem an inevitable byproduct of the upcoming schedule. Not even Robert Lewandowski can be expected to maintain his super-human fitness levels in such a demanding environment.