Gernot Rohr suffered only his second loss in 14 matches as Super Eagles coach when Nigeria went down 2-0 to Serbia in London on Tuesday.
Beyond the result, there was plenty to unpack in this unexpected capitulation, with the West Africans learning some tough lessons with the World Cup less than three months away.
Here are the hot talking points from Nigeria's Serbian setback as the Road to Russia continues.
Nigeria's passing must improve
It's hard to remember too many occasions against Serbia in which Nigeria managed to string more than three passes together.
Without captain John Mikel Obi for the second game in succession, the Nigerians looked like they had no concept of the basic fundamentals of a passing game.
Moves constantly broke down, especially under high pressing, because players appeared unable to pick out a teammate under pressure.
It's not just the player in possession who was to blame, with a lack of movement off the ball also limiting options.
We have seen this team pass the ball better, against African opposition and against Argentina, but without Mikel, they lacked cohesion and confidence with the ball at feet.
When his team gets back together in May, Rohr will have to fashion out a way to have his players keep possession better, move the ball better and create chances.
Rohr shows flexibility with tactical tweak
Tuesday's starting XI represented something of a surprise as Rohr diverted from his usual approach.
In his previous 13 games with Nigeria, the German tactician has always started with a leading big man flanked by wide forwards in what was essentially a 4-2-3-1.
That line-leading position has been played by Odion Ighalo, Kelechi Iheanacho and Anthony Nwakaeme.
Against Serbia, however, he chose to go with Ahmed Musa in that central position in a more traditional 4-3-3. It would seem to appear that the Nigeria coach wanted to see if he could exploit the somewhat slow Serbian defence with pace and a bit of guile.
Musa's pace did trouble Branislav Ivanovic and his partners, but the trouble was that in deploying Wilfred Ndidi as the most advanced midfielder, Rohr sacrificed a creative link to those forwards.
Perhaps Joel Obi would have been better served up there, even though he misplaced a slew of passes by trying to do too much.
Could have also have deployed Alex Iwobi in this role?
Rohr ultimately discarded the experiment after 45 minutes, replacing Victor Moses with Ighalo and reverting to type.
Iwobi can be Mikel 2.0
Iwobi may not have been detailed to play there, but the Arsenal man regularly nipped centrally, to orchestrate play. He skipped away from opposing players with fancy footwork, played combination balls and generally conducted proceedings.
The trouble was, he was not supposed to be there, and kept bumping into the hapless Wilfred Ndidi. It was an impressively exquisite performance of ability, skill...and ill-discipline.
Over two games, the Super Eagles suffered from not having a player with the authority to control the play, to stabilise the game and ease pressure under unrelenting attacks.
That player is usually Mikel. On Tuesday, Iwobi showed that while he does not have Mikel's calm maturity to stabilise the play - at least not yet - he does have the ability to dictate play.
His quick passing, close control, skilled getaways from tight marking and combination passing were not perfect, but they provided a glimpse into what is possible if he were to be employed in this role.
On Tuesday, he showed tactical indiscipline by drifting inside too often rather than stretching the play.
However, it's not impossible that Rohr might opt to use Iwobi inside and employ Moses Simon and Moses in wide areas to offer pace on the flanks.
Lack of success aside, Rohr's choices showed that the coach is actively exploring the possibility of surprising some of his opponents.
This certainly bodes well for the hopes of a multifunctional player like Joel Obi to gatecrash the Russia party.
Uzoho isn't yet ready
Francis Uzoho: Talented? Yes. Future prospect? Yes. Current first-choice? Absolutely not!
The wonderkid is growing in stature, but as expected, Uzoho is nowhere near ready to be the Super Eagles' number one goalkeeper going into the World Cup.
After 225 minutes of football, the 19-year-old still looks like the inexperienced goalkeeper that he is.
He mistimed crosses, misjudged balls and for the second time in two games, showed butter fingers as he let an effort slip under him and over the goalline.
Fortunately, there was no goalline technology to rule the effort in.
One area he did excel in was shot-stopping. On the occasions when he faced down strikers one on one, Uzoho read the threat brilliantly and smothered efforts with panache and confidence.
It would appear Uzoho is heading to Russia with the Super Eagles, and while he deserves to make the trip, he'd be a clear weak link if he starts.