As Barcelona fell to a fatigued, lacklustre 2-1 defeat at Deportivo on Sunday, there was an underlying sense that something integral was missing. Was it Samuel Umtiti, the centre-back whose presence in the starting lineuphas brought with itexclusively wins? Maybe.
Was it the absence of Andres Iniesta for 58 minutes, and the inclusion of the yet to impress Andre Gomes? Possibly. Or was it the lack of a certain Brazilian forward, so instrumental in the heroics four days earlier? Probably.
Neymar's importance to Barcelona has become increasingly evident in recent weeks, as the season has grown increasingly bizarre. It was in his absence that it was perhaps most evident. MSN was just MS, not the same.
There was a clear lack of balance about Barcelona against Deportivo, an unusual uncertainty, made even more notable without Neymar. It was inevitable really, but the now 25-year-old is now undoubtedly on his way to becoming the main man, the poster boy, the messiah at a club always looking for someone to worship.
In last week's still hardly believable 6-1 win against PSG, it was Neymar that instigated the impossible. His superb free-kick to make it 4-1 seemed like a consolation, but looking back now, that moment of crucial individualistic brilliance was what might have been expected of Lionel Messi. The Argentine is, of course still brilliant, as is Luis Suarez, but Neymar's influence in such a big game was symbolic of his ever growing reputation.
The fifth goal came under controversial circumstances, Suarez's theatrics largely considered to be a dive. But Neymar was there to score his penalty, with the composure of a player who knows his own incredible ability. It was telling that it was he, not Messi that took the most important penalty of the night. Neymar has matured, developed, to the point where he is now reaching his enormous potential.
It was the sixth goal that most emphatically proved the point. He was the player playing the final ball, the man given the responsibility to pick someone out under such circumstances. He did it perfectly, weighting his left-footed pass to perfection for Sergi Roberto to provide the unforgettable, historic finish.
Neymar had been heavily involved in all three of the last goals, and you get the feeling that, without him, the most memorable game in Champions League history wouldn't have happened.
Neymar's game by numbers vs. PSG:
7 crosses
6 shots
4 take-ons
3 tackles won
2 chances created
2 goals
1 assist
Neymarvellous.  pic.twitter.com/zy6kihRYub
This wasn't the case in Luis Enrique's first season as Barcelona coach. M, and even S, were the most emphasised letters when discussing the front three, but now the absence of N has become noticeably damaging. Neymar has largely been the catalyst for the continued excellence of Suarez and Messi this season, which can often go unnoticed.
Indeed, his goal scoring record is still not at the level of his fellow forwards - 14 in all competitions this season, compared to 39 and 33 for Messi and Suarez respectively. His 16 assists are, however, impressive, but statistics are not really the point.
Messi and Suarez would score goals without Neymar, and would still be at the top of the world game for a good few years to come. With him, though, they are made even more effective, as is Barcelona's attack.
In the first leg against PSG, a dominant 4-0 win for the French side, Barcelona were toothless. That is except for Neymar, the only player who offered any resistance to Unai Emery's structured defence. He was unable to make an impact in that particular game, but emerged as one of the few players with any credit, and took that into his stunning second leg performance.
Marca : "After Barcelona's come back against PSG , Neymar deserves to be nominated to win the Ballon d'Or this year " @neymarjr pic.twitter.com/brJ4fJcFq0
That performance wasn't his first of significance in a Barcelona shirt; he has been very good since his arrival. What it certainly was, was his most significant, and one which pointed towards a visible change at the Catalan club. Suarez is in his 30s, Messi is rapidly approaching them.
Neymar, meanwhile, is entering his prime; 25, a Brazilian enigma, and a future Barcelona talisman. Whereas before the irrepressible Barcelona trio might have been considered as Msn, or indeed MSn, the N is quickly becoming more and more prevalent.
If Messi and Ronaldo relinquish their unyielding grip on the Ballon d'Or in the coming years, don't be surprised to see Neymar as the man punctuating their dominance.