Jordi Alba is set to undergo further tests on a suspected hamstring injury on Wednesday after being forced to leave the field in the first half of Barcelona's 0-0 stalemate with Borussia Dortmund.
Tuesday's Champions League clash at Westfalenstadion saw the two favourites for top spot in the group fail to find the back of the net, mostly due to the heroics of Marc-Andre ter Stegen, who saved a Marco Reus penalty midway through the second half.
Securing a point away at their nearest rivals will be considered a good result for Ernesto Valverde's side, but the injury sustained to Alba will be a blotch on an otherwise credible night.
Having initially gone to ground on the half-hour mark, the left back insisted on playing on after receiving treatment, only to signal to the bench to be substituted a few minutes later, with Sergi Roberto coming on in his stead.
While the extent of the lay-off facing the 30-year-old is to be discovered in due course, it's still a major blow to Valverde's side in both Europe and La Liga. Alba has so far played every minute of the club's league campaign, with La Blaugrana registering two wins and a draw from their opening four matches.
Next up for Barça is an away trip to Granada on Saturday, where the club will also be without Ousmane Dembele and Samuel Umtiti, who are recovering from hamstring and foot injuries respectively.
On a brighter note for Valverde, Lionel Messi made his return to first-team action in their Champions League draw, replacing 16-year-old Ansu Fati in the second half having been sidelined with a calf injury he picked up on international duty with Argentina during the Copa America.