Nigeria's Super Eagles pulled off a stunning come-from-behind victory over Argentina on Tuesday night in Krasnodar.
The victory was as unexpected as it was electrifying, as Arsenal's Alex Iwobi scored twice to see the Nigerians to a 4-2 win, after trailing 2-0 early on.
Rohr building depth in weak areas
When Rohr took over this young team, and all through his tenure, there have been deficiencies in certain areas of the squad.
Right back was non-existent, as Shehu Abdullahi appeared to merely be a cover until Musa Mohammed could get a regular run of games at club level. So far, that has not happened.
Elderson Echiejile was the only left back of quality, Carl Ikeme was pretty much the only goalkeeper worth noting, and the lone striker position had only Kelechi Iheanacho on the teamsheet.
Rohr set about rebuilding the team, almost from scratch, and with very young players. Tuesday's game, against quality opposition, showed that the job is more than halfway done.
Tyronne Ebuehi was excellent at right back in his 45-minute spell after he took over from a consistently impressive Abdullahi.
Ola Aina was just as impressive in his third cap at left wingback, before giving way to Brian Idowu, who not only defended with grit and intelligence, but showed he could be a menace in the penalty box, scoring a goal on debut.
Chidozie Awaziem exorcised the ghost of his abysmal debut against South Africa, giving an extra option at centreback, while Kenneth Omeruo proved that the game time he has been getting in Turkey is no fluke.
While the goalkeeping spot still has a question mark hanging over it, Francis Uzoho showed with his first cap that he could well skip a few places on the queue.
Nigerians have become used to newly-appointed coaches using 'rebuilding' as their 'get out of jail free' card when they're appointed, just in case things don't go well. Rohr didn't exactly talk that talk, but he has most certainly walked the walk.
Questions over Enyeama remain
A good 'keeper can be the difference between getting all the way to the World Cup final in Russia, or going home after the Group phase.
At the moment, Nigeria lack a goalkeeper of World Cup quality. Their only world class stopper, namely Vincent Enyeama, has retired and, from all indications, is determined to remain so.
Uzoho showed that he might just have the ability to get there. But make no mistake, he is not there yet, and will make errors down the line.
However, between Ikechukwu Ezenwa, Dele Alampasu, and Uzoho, the Super Eagles have a base to build on. Throw in Daniel Akpeyi and Dele Ajiboye, and that competition can become fierce enough to bring out the best in at least three of them.
Rohr must look beyond Enyeama and find a way to motivate, and ensure his current keepers get the training and exposure they need between now and June, even if it means playing easy friendlies.
Super Eagles need to deal with the high press
Argentina totally controlled the game for most of the first half, with their high press and sharp passing. The Super Eagles failed to get to grips with those, especially with the pressing.
Rather than create space and switch balls to beat the press, they tried to pass short within the same pressing zone and ended up getting smothered and coughing up possession.
It is an area that Rohr needs to work on. At the World Cup, there will be teams who will press with as much intensity, those who will pass with even more precision, and the ones who will suffocate with denial of space.
The Super Eagles were all over the place at the height of the Argentina passing game. Players did not hold their lines, arrived late to tackles, and ended up mistiming them. They needed to be closer to individual players, but strayed too far away and gave them way too much time on the ball.
Impressive tactical flexibility from Rohr
Throughout his time with Nigeria, Gernot Rohr has not deviated from a 4-3-3, but on Tuesday, he went with a 5-3-2, with three centrebacks, two wingbacks, and two forwards.
While this may have been a tactical switch to counter Jorge Sampaoli's high press and wide overload, it might just end up becoming the ideal formation for Nigeria, based on current personnel.
Victor Moses has excelled as a wingback at Chelsea, but could benefit from having additional protection behind him in Abdullahi and Awaziem.
It also offers cover for both Echiejile and Leon Balogun - two somewhat slow players who patrol the left side - with Iwobi and possibly Onazi covering for them while providing overloads when going forward.
For a new system, the team suffered in the early stages of the first period, but improved as the half aged, and even though they switched formation later, they were looking increasingly comfortable.
Nothing has really been won...
Nigeria can celebrate beating Argentina from now till kingdom come, but remember this, nothing has been won yet. This was a friendly. That is all.
Argentina are a strong team, irrespective of their troubles, and they put out a fairly strong lineup, one that included the likes of Aguero, Mascherano, Otamendi, Pavon, Di Maria, Banega, and Dybala. But friendlies are friendlies.
The Super Eagles can and should celebrate the victory, because they most certainly would have been hammered by fans if they had lost.
But they must stay humble, keep their feet firmly on the ground remember that the big prize is still ahead.