Bruno Genesio is looking to comeback kings Ajax and Manchester United for inspiration as Lyon seeks to bundle Barcelona out of the Champions League.

The youthful Ligue 1 side held its far more fancied opponents to a goalless draw in the first leg but is considered unlikely to survive a tough return trip to Camp Nou on Wednesday.

Head coach Genesio is bullish about his team's chances despite the odds being stacked against the side and cited last week's second-leg upsets as providing cause for belief.

Ajax overturned a 2-1 deficit to stun Barca's LaLiga rival Real Madrid, while Ole Gunnar Solskjaer's United bounced back from a 2-0 home defeat to dramatically oust Paris Saint-Germain.

"It shows anything is possible," Genesio said.

"Nobody gave Manchester United a chance and they did it. We saw how Ajax eliminated Real Madrid. It gives us extra hope even if each match and the context is different.

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"You have to have confidence. You have to take calculated risks. This is how we have to approach the match.

"We need to play a perfect game."

Lionel Messi is the clearest threat to Lyon's hopes of causing an upset but Genesio dismissed the possibility of employing man-marking tactics.

Barca's superstar skipper has scored four goals in as many games since an uncharacteristically quiet showing in France last month.

"Many things depend on Messi. He's an extraordinary player," the Lyon boss said.

"We'll develop a gameplan to reduce his influence. We won't mark him individually, that's for sure. We have to work collectively to stop him."