A foot problem has ruled the Brazil star out of action for the next four weeks, while defender Jordi Alba is also set for a similar absence with a torn hamstring.
The 22-year-old endured a miserable night on Wednesday as Barca was beaten 2-1 by Real Madrid, with the Brazil star guilty of missing a glorious chance in the final minute of normal time.
Neymar's misery has now been further compounded by the news he will miss the games against Athletic Bilbao, Villarreal, Getafe and Elche, though the club will be hopeful of him returning for the final day clash with Atletico Madrid.
A statement on Barcelona's website said: "The player suffered a concussion that caused an edema in the fourth metatarsal in his left foot that will require specific treatment. Recovery time is approximately four weeks."
Jordi Alba was withdrawn at halftime in Wednesday's defeat and a further examination has revealed the left back suffered a torn hamstring in his right leg.
As a result, the former Valencia man will also be out of action for a period of three to four weeks.