Olympique Lyonnais showed their best and worst sides as they squandered a two-goal lead in a 2-2 Ligue 1 draw at Strasbourg on Saturday ahead of their Champions League clash with Barcelona.
Moussa Dembele's double was cancelled out in the space of 103 seconds in the second half when Ludovic Ajorque also netted twice after Lyon lost centre-back Marcelo to a thigh injury.
"We will review the situation tomorrow. Marcelo will undergo checks to determine the nature of his injury," coach Bruno Genesio said.
"His absence [against Barcelona] is not certain yet."
The result put third-placed Lyon on 50 points from 28 games, four behind second-placed Lille, who could open a seven-point gap when they travel to Saint-Etienne on Sunday.
At La Meinau, Genesio took a cautious approach before Wednesday's last-16 game at the Nou Camp after a goalless draw in the first leg when he left forward Bertrand Traore, Memphis Depay, Nabil Fekir and midfielder Tanguy Ndombele on the bench.
Marcelo limped off the pitch in the 16th minute to be replaced by Leo Dubois.
Lyon were already ahead after Dembele had opened the scoring in the third minute by deflecting a Maxwel Cornet strike.
The visitors controlled the game and came close several times but Strasbourg keeper Matz Sels made a few good saves to keep his team in the game.
He was powerless, though, when Dembele beat him from the penalty spot six minutes into the second half after Lamine Kone had brought down Hassem Aouar.
Ajorque deflected an Adrien Thomasson header with his shoulder to reduce the arrears in the 69th minute he equalised with a powerful left-foot shot.
Fekir came on in the 76th minute and Traore in the 82nd but neither could make a difference and Strasbourg hung on for the draw. They are ninth in the standings on 38 points.