Forward Martin Terrier appeared to collapse with nobody around him during Lyon's clash with Toulouse in Ligue 1.
Former Celtic star Moussa Dembele was reportedly visibly upset as Terrier was treated on the pitch before the game continued at the Stade Gerland.
Medics rushed onto the field to check on the 22-year-old who woke with a spasm following the incident.
He was awake when he was taken off after initial treatment on the pitch.
There was clear concern for the forward, but it appears there is good news about his condition.
According to Margot Dumont of BeIN Sports the signs were reassuring after Terrier had gone off, with the broadcaster reporting that the incident represented "more of a scare than anything bad".
The French club later confirmed that there was no danger to the youngster.
They wrote on Twitter: "Earlier Martin Terrier was the victim of a vasovagal reaction during OL vs Toulouse.
"Our player's condition has improved and he is awake."
The vasovagal reaction causes an abrupt dropping of the blood pressure and a sudden reduction in heart rate, meaning less blood flows the brain.
This can cause fainting, which appears to be what happened in Terrier's case.
The 22-year-old has played for France's Under-21 side but has yet to make his full debut for Les Bleus.
