The Napoli striker may have been the obvious bet to finish as the tournament's top scorer, having netted 10 times in qualifying, twice as many goals as the next most prolific marksmen.
Nevertheless, he has found the net just once going into Friday's last-eight tie against outsiders Angola in Abidjan.
However, that does not tell anything like the whole story of the masked forward's AFCON so far.
Osimhen scored in Nigeria's first match in Ivory Coast, which ended in an underwhelming 1-1 draw against Equatorial Guinea.
He won the penalty which captain William Troost-Ekong scored in the 1-0 victory over Ivory Coast, and then played all 90 minutes of the final group game against Guinea-Bissau when he could well have been rested.
Osimhen then turned in an awe-inspiring performance in the 2-0 last-16 win over the Super Eagles' old rivals Cameroon, harassing and pressing the opposition defence all evening and setting up the opening goal.
"He didn't score but he had a fantastic game. It is not easy to stop that guy! Ask the defenders of the opposition how they suffer," said Nigeria's charismatic coach, Jose Peseiro.
The Portuguese manager has made clear that he sees not conceding goals as the key to success at the tournament, despite boasting an embarrassment of attacking riches beyond Osimhen.
But his tireless number nine is the first line of defence with the amount of running he puts in, which is all the more impressive in the sapping heat and humidity of West Africa.
Ultimate team player
Osimhen collapsed to the turf at the Felix Houphouet Boigny Stadium when the half-time whistle went against Cameroon, but recovered suitably to continue chasing down the opposition defence in the second half while also whipping the Abidjan crowd up into a frenzy.
"Osimhen plays with passion. That's what every country wants their players to do," former Ghana striker Asamoah Gyan, Africa's all-time top scorer at World Cups who played in two Cup of Nations finals with the Black Stars, wrote on X.
As for the goals, Osimhen and Nigeria will hope he is saving them up for the final stages of the competition.
According to data made available by statisticians at Opta Analyst, Osimhen has had 15 shots at this AFCON, at least two more than any other player.
Only three of those have been on target and he has just that one goal, but his "expected goals", or XG, is 2.78, the highest in the tournament - higher even than five-goal top scorer Emilio Nsue.
More than anything, however, Osimhen's performances and his incredible work-rate back up what he told AFP in an interview at the Nigeria team base earlier in the tournament.
"I don't want to put myself in the centre but of course a lot of people say this. But I think more like a team player," he said.
"I really don't care even whether I start or not. For me to be there playing with them is a big one for me. I just want to keep on helping the team."
As modest as he may be, Osimhen has to be the first name on Peseiro's teamsheet as Nigeria eye their fourth continental crown.
