Despite banking 222 million euros for the Brazilian, Barça's scattergun approach to finding a replacement has so far been unsuccessful with bids for Liverpool's Philippe Coutinho and Ousmane Dembele of Borussia Dortmund so far rebuffed.
New Barça coach Ernesto Valverde must therefore try to down the European and Spanish champions with a weaker squad than the one which missed out to Real for the La Liga title last season.
However, Barça did manage to beat Madrid without the then-suspended Neymar the last time the sides met in competitive action back in April as Lionel Messi won an incredible encounter 3-2 with the last kick of the game.
The Catalans also edged last month's Miami friendly between the two in Neymar's last game for Barça 3-2.
Valverde's men completed a perfect pre-season on the field with a fourth straight win by sweeping aside Chapecoense 5-0 on Monday in a match to raise funds for the stricken Brazilian club who lost 19 players and 24 club officials in a plane crash last year.
"We've had a good pre-season and we are coming into the game in good condition," said Valverde.
"But on Sunday the real thing starts, with a competitive game and a title at stake against our biggest rivals."
Gerard Deulofeu was handed Neymar's role alongside Messi and Luis Suarez up front against Chapecoense on his return to the club after spells at Everton and AC Milan.
And the Spanish international took his chance with a goal and two assists in just 45 minutes on the field.
"It is always a pleasure to play here and even more so with these players," said Deulofeu.
Valverde is likely to stick with Deulofeu, but the former Athletic Bilbao coach could also strengthen Barça's midfield by sacrificing a forward to add Sergi Roberto to the normal midfield three of Sergio Busquets, Ivan Rakitic and Andres Iniesta.
Despite failing to win any of their pre-season games, Madrid started the new campaign as they ended last season with another trophy as Zinedine Zidane's men proved too strong for Manchester United to win the UEFA Super Cup 2-1 on Tuesday.
Casemiro and Isco were on target as Madrid's midfield dazzled in Skopje, Macedonia, but Zidane will be forced into at least one change from the side that started in midweek as Luka Modric is suspended.
Should Zidane wish to maintain the 4-4-2 system he has utilised to huge success in 2017, Mateo Kovacic is the favourite to replace his Croatian teammate in midfield.
However, Modric's absence increases Cristiano Ronaldo's chances of returning to the Madrid starting XI after making just a brief cameo appearance as a substitute against his former club in Macedonia.
Ronaldo only returned to training with his teammates last weekend on their return from a tour of the USA having been given an extended break following Portugal's participation in the Confederations Cup and a court appearance in Madrid over allegations of tax evasion.
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