Marseille’s Ligue 1 home match with Lyon was postponed after visiting boss Fabio Grosso was injured when his team’s bus was attacked on the way to the ground.
Images on social media showed a bloodied Grosso laid on a stretcher.
According to AFP, the Lyon coach was hit by rocks on its way to Stade Velodrome.
The game between bottom-of-the table Lyon and 10th-placed Marseille was due to kick off at 19:45 GMT on Sunday.
“These are completely unacceptable circumstances,” said Marseille club president Pablo Longoria.
“My first thought is for Fabio Grosso, someone I respect and have known for a long time. I went to see him as soon as I arrived at the stadium, I saw how he was.”
Following the attack a crisis meeting was called where it was decided the game should not go ahead.
“During the meeting following the incidents that occurred outside the Velodrome stadium on the route of its bus, Olympique Lyonnais made known its opposition to taking part in the meeting given the circumstances,” a French league statement said.
It added its Competitions Commission would decided the next steps.
‘Terrible image for French football’
Thousands of fans were already inside the ground when the announcement was made that the game had been postponed.
“We took into account Lyon’s desires for the match not to take place,” said match referee Francois Letexier at a news conference.
“Based on Lyon’s wishes and the protocol, the decision was taken not to start the match,” he added, adding that reports “have been forwarded to the relevant authorities who will decide what action to take”.
AFP reported a Lyon club source as saying Grosso, the former Italy defender, was experiencing dizzy spells.
French football expert Julien Laurens, writing on X, described it as a “terrible image for French football”.
“What a scandalous mess,” he added. “This is not the first time this has happened (and not the last sadly) but I have no words for this. Unacceptable again.”
Seven-time champions Lyon last won Ligue 1 in 2007-08. Grosso, 45, was appointed as their managed in September after former France centre-back Laurent Blanc was sacked.