Rangers could be without Ryan Kent for the start of their Scottish Premiership campaign after the winger was sent off in Thursday’s 2-0 win over Lyon.
Kent, 23, was dismissed just before the break after pushing defender Marcelo in the face after a heavy challenge.
Should the red card be reported to the French FA by the referee, he faces a two-game domestic ban.
“I thought the referee overreacted but it’s hard to defend Ryan,” said assistant manager Gary McAllister.
“The defender came through the back of him and provoked him, then there were handbags. But as soon as you raise your hands and touch your opponent in the face, it’s a red card.”
Kent – who forced Marcelo into an own goal before Ianis Hagi doubled the lead – would miss the Premiership opener at Aberdeen and the visit of St Mirren a week later.
Before Rangers’ win at Groupama Stadium, Celtic began their pre-season campaign in the same venue with a 1-1 draw against Nice.
Kasper Dolberg gave the French side the lead after Odsonne Edouard had an effort disallowed, before Patryk Klimala scored a second-half leveller.
It was Klimala’s first senior goal for the club since his January arrival from Jagiellonia and manager Neil Lennon expects more from the Pole this season.
“It’s a forte of his game, being aggressive with his pressing. He got what he deserved,” Lennon said.
“He’s a work in progress. It’s a different style of football from what he was used to in Poland but his attitude was brilliant and I think over the piece he will contribute well.”