MADRID, Nov 20- Real Madrid midfielder Mahamadou Diarra has said that a second group defeat against his former team Olympique Lyon is an unthinkable prospect despite the French side's flawless record in this season's Champions League.

"Last time we met we weren't at our best," the Mali international told a news conference on Monday. "But things are different now, we are now a true team, we are more solid and we are playing at home.

"The results show that things are going well now and we have to prove that against Lyon. We will be out for revenge and certainly don't want to lose to them again. A good team can't lose twice in a row to the same opponents."

The nine-times European champions have met the French side three times over the course of the last two seasons, but have yet to notch up a victory.

Last year they were crushed 3-0 at the Stade Gerland and then drew 1-1 at the Bernabeu, while this season they lost 2-0 in Lyon in their opening group match.

Lyon top Group E with four wins from four games and have yet to concede a goal.

Both sides have already earned their places in the knockout phase, but Real will need to beat the French champions by at least two goals if they are to wrest top spot from their grasp.

Like Diarra, coach Fabio Capello also feels Real have made significant improvements since the last time the sides met.

"It is clear that we are a very different side now," said the Italian. "The players know each other better now and we have got something extra too."

But Capello said avenging previous defeats was not a consideration.

"This isn't a revenge match," he said. "We just want to show that that we are a better side than we were in the first game. The important thing is that we are in the next round. It is important to win tomorrow too, but not vital.

"People always say that finishing first in the group makes it easier because you play the second leg of the knockout game at home, but the players shouldn't be thinking about things like that."