St Etienne attacker Romain Hamouma says some Lyon players deserved "slaps" for the way they behaved during Sunday's Rhone derby.
A hat trick from Alexandre Lacazette saw Lyon to climb to second in Ligue 1 with a 3-0 home win over their local rivals.
St Etienne's players and management had no complaints about the result in what was the last derby match to be played at the Stade de Gerland before Lyon move to a new stadium in January.
But they were unhappy with a Jordan Ferri tackle on Slovenian attacker Robert Beric.
According to visiting manager Christophe Galtier, Beric will definitely miss his country's upcoming Euro 2016 playoff matches against Ukraine.
If St Etienne's worst fears are confirmed, however, the 24-year-old could end up sitting out the rest of the season with a cruciate ligament injury.
Galtier was also "very angry" that another incident involving Lyon defender Mapou Yanga-Mbiwa went unpunished, while he accused Ferri of gloating about his side's win.
Ferri was not the only person to annoy Saint Etienne's players for the way Lyon celebrated their victory in the 111th derby match between the sides.
"There are a lot of things that are difficult to take -- in terms of behaviour too," Hamouma told reporters.
"There are good guys on the pitch but there some, honestly... slaps would been deserved. We'll come to terms with this defeat. They were better than us but we'll be waiting for them in the return match."
When asked if Ferri was the problem, Hamouma, 28, confirmed that he was not the only one.
"Not just [Ferri] -- there are others too," he said. "But we haven't forgotten it. When we win, we celebrate with our fans. We stay humble because we know things can go quickly.
"But at their place, no, they do it differently. We'll remember that."
Saint-Etienne captain Loic Perrin was also displeased by the way some of Lyon's players had acted.
"What I regret in particular is their attitude -- there was a lack of respect from some players," he told reporters after the game.
"Not from all of them, but from some of them... I think you have to be dignified in victory and some of them weren't."
Ferri, 23, received a yellow card for his tackle on Beric. He said he was not the type of player who goes out to hurt opponents.
"I'd like to apologise for the injury to Robert Beric because I didn't intend to hurt him. I'm not a nasty player," he is quoted as saying by Canal+.
The Lyon midfielder also defended himself over his exchange of words with the visiting bench late in the match.
"It wasn't me who started it," Ferri said. "When you insult members of my family, I react."
Lyon boss Hubert Fournier responded to St-Etienne's concerns by stressing that Ferri's version of events was very different.
"It was up to him to keep his cool and not to fall for deliberate provocation from the Saint-Etienne bench," Fournier told a news conference.
"They're the squabbles that we're used to in a committed derby game."