Former Rangers and Lyon man Sebastien Faure has warned the French side they risk being overwhelmed at Ibrox on Thursday night.
The defender spent three years in Govan having come from the OL academy, giving him a unique insight into both clubs.
And while the 30-year-old believes the Ligue 1 giants have more quality, he insists the raucous Ibrox atmosphere and the intensity of Steven Gerrard 's side could render that moot.
Asked what OL could expect from the Europa League opener, Faure told Olympique et Lyonnais: "A big atmosphere, right from the start.
"Any European game at Ibrox is very complicated to play and they love to rub shoulders with European teams. Lyon is considered a big team from the Old Continent over there, a team that should play in the Champions League with a big squad, a lot of money, a big stadium.
"OL will be very well received with a very, very strong atmosphere in the first 30-40 seconds.
"There will be a lot of noise.
"Rangers will be Lyon's toughest opponents because they have to go and play at Ibrox and that's not easy.
"I think the other two teams in the group (Sparta Prague and Brondby) are more easy to deal with but going away to them won't be easy either.
"Clearly, Lyon are favourites. They have better players, they have a better team, a better collective.
"But away matches in Europe are always quite complex, especially at Ibrox.
"OL will have to match the intensity Rangers will bring.
"They will be pushed on by their fans and they will be 150 per cent from the first to the 95th minute. If there is not the same intensity (from Lyon), they won't be able to play out and it will not be possible to impose their game.
"If the Lyonnais get beaten in the duels, Rangers will get a big psychological boost while the opposition risk playing on their heels.
"Rangers are going to be a team that will really go at OL."
The three years Faure spent at Rangers were not the most glorious, but the Frenchman was nonetheless struck by the sheer size of the club.
He explained: "When I arrived the club had big financial problems. Rangers had to go down to the lowest professional level, the fourth tier, the equivalent of National 2 in France.
"At that time, the club had had to stop the season ticket sales that had been set up because the demand was too high.
"Rangers couldn't use the whole stadium for season tickets and with 30-40,000 signing up, they had to stop to make places for others.
"What struck me was that the stadium, especially in the first year, averaged 46,000 spectators in the fourth tier across in 18 matches.
"It was mind blowing.
"They say that sport is a religion but it is kind of true there, unlike in France.
"Rangers have been legendary for years. They won many titles, a European trophy.
"It's mythical thing and it is handed down from generation to generation. The great-grandfather is Rangers or when the little one is born, he he's Rangers from the age of six months. It's generational. They follow their team until the end."
