Every indication suggests that the Brazilian will start the match at the Bernabeu, despite being an unused substitute in last week's 7-0 thrashing of Osasuna.
Martino backs Neymar: "He's one of the five best in the world" http://t.co/KnWgzmd5m4 - Barça's boss hints the forward will start on Sunday— AS English (@English_AS) March 22, 2014
Not least because of Tata Martino's pre-game comments to reporters on Saturday: "I will repeat something I said: Neymar is one of the five best players in the world. I don't need any middle party to confirm his qualities."
This praise from his manager would suggest the 22-year-old will line up in the starting 11 on Sunday and he will need to turn his form around to repay that faith.
This El Clasico will be key in deciding the destination of the La Liga title this season, and a loss for Barcelona will see them effectively out of the race.
They currently sit third, four points behind leaders Madrid. And the quality of Carlo Ancelotti's side this season suggests that Barcelona will have to win to maintain their title ambitions.
Neymar could kick-start a strong end to the season if he can perform well and help his side to a victory.
Respond to the El Clasico Pressure
Neymar was at the centre of everything in the reverse fixture back in October as Barcelona won 2-1 at the Nou Camp.
He scored one and assisted Alexis Sanchez for the other on that occasion, per ESPNFC.
He will need that kind of performance this time around if he wants to throw off the doubters who are unconvinced that the £71 million Barcelona eventually paid for him was worth it.
Neymar - where the £71m went pic.twitter.com/16jLO6DKX1— InsideWorldFootball (@insidewldftball) March 20, 2014
And he has the ability to put on such a display.
While 2014 has been a lean year in his Barcelona pursuits, he did score a hat-trick for Brazil against South Africa in March.
Neymar scores hat trick as Brazil rolls past South Africa in Johannesburg. http://t.co/c9Ah4EFmO1— FOX Soccer (@FOXSoccer) March 6, 2014
If he can get his scoring boots on and return to his elusive best he could be very influential.
He seems to be a player who rises to the big occasion and there is no bigger occasion in club football than when Barcelona take on Real Madrid.
Rise above Bale and Ronaldo
Gareth Bale and Neymar both arrived in La Liga last summer and both were billed as superstar partners for the world-beating Cristiano Ronaldo and Lionel Messi respectively.
So far this season the received wisdom seems to suggest that Bale has contributed more to Real than Neymar has to Barcelona.
This is the moment when Neymar can change that perception.
Bale is a better signing than Neymar, say Goal readers http://t.co/KVrRdTop5f— Goal (@goal_intl) March 23, 2014
If Real run out easy winners with Bale and Ronaldo running the show, the argument will have been won.
But if Neymar can link up with Messi and dictate a win for Barca it could signal a change in momentum over the season.
Ronaldo and Bale's combined league goals total for the season is 35 compared with Messi and Neymar's total of 25, per ESPNFC.
Who will win El Clasico?
On stats alone, the Madrid pair are winning. But the destination of the title is the real battle and a performance from Neymar could propel Barcelona to just one point off the top.
Sunday's game is a huge test for the Brazilian star. A time for him to prove the doubters wrong.
And despite his recent form he has the faculties and the motivation to put in a match-winning performance.