Philippe Coutinho will be out of action for the next two-to-three weeks after suffering a muscle injury in his leg, Barcelona have confirmed.
The Blaugrana conducted tests on the Brazilian on Thursday and discovered he has "a small rupture in the femoral biceps of his left leg."
If he fails to return in time for that match, he may be ready for when Barca travel to PSV Eindhoven in the Champions League on November 28 or when they host Villarreal on December 2 in La Liga.
Coutinho arrived at the Camp Nou from Liverpool in January and has produced 15 goals and 10 assists in 38 games, five and four of which have come this season, respectively.
The playmaker's form has been wanting in recent weeks, though he put in a stronger showing against Inter Milan on Tuesday in Barca's 1-1 draw:
Squawka's Muhammad Butt did take issue with his decision-making, however:
Nevertheless, Coutinho is an important player for Barcelona as one of their chief creators. His absence will be a blow to the side, particularly if he can't make the Atletico match—it often takes a moment of genius to unlock their resolute back line.
That said, the timing of his injury is convenient for Barca because of the international break.
If he does recover in time to face Los Rojiblancos, he'll only have missed one game and won't have been travelling with Brazil, either.
While he's out, Barcelona will be thankful Lionel Messi is back training with the side after his broken arm, as they could ill afford to be without him and Coutinho.