The winger fell to the ground clutching his hamstring after sprinting for the ball mid-way through the first half.
It was just his second start for the Catalan giants, but this one ended on a sour note for the Frenchman.
Ernesto Valverde did not hesitate and immediately brought on a replacement in Gerard Deulofeu, who could now be in for an extended run in the starting XI.
Barcelona have released an update on Dembele's situation and it's not happy reading for fans.
Ousmane Dembélé has a hamstring injury in his left leg, more tests are needed to find out the extent of the injury #FCBlive pic.twitter.com/tekYrp6AHQ
— FC Barcelona (@FCBarcelona) 16 de setembro de 2017
The tweet reads: "Ousmane Dembele has a hamstring injury in his left leg, more tests are needed to find out the extent of the injury."