French rugby team Racing 92's New Zealand fly half Dan Carter (2nd L)

Racing 92 are operating at just 50 percent of their potential according to kicking coach Ronan O'Gara.

The Parisians face a crunch clash against Leicester Tigers in the European Champions Cup semi-final on Sunday but former Ireland international fly-half O'Gara believes they have plenty more in the tank despite a hugely positive season so far.

"I think we're at 50 percent of our potential. There are many, many things to improve on," said the 39-year-old, who joined Racing's backroom staff after hanging up his boots in 2013.

"The most important thing is that this year there is the desire, there's better organisation on the pitch as well and a better team spirit.

"If we mix all that together and add a good strategy, everything becomes possible.

"Everyone knows it, I'm demanding -- 50 percent is perhaps quite severe. But I know that if we push the lads, there's more to come. I'm convinced that if we work hard, the results will follow."

Racing have been masterful in Europe this season, winning their pool comfortably ahead of Northampton Saints and then defeating reigning three-time champions Toulon 19-16 in the quarter-finals.

They have also been going well in the league, although they currently sit fourth in the Top 14 table after a recent blip saw them lose three of their last four matches.

However, they remain on course for the end of season play-offs and perhaps a first title in the Top 14 era, not to mention European glory.

But O'Gara says they've achieved nothing yet.

"We've won a quarter-final, great! But that's it. They only good thing is that we've beaten the greatest champions this competition has ever seen," said O'Gara, who won 128 caps for Ireland and featured in three British and Irish Lions tours as a player.

"What Toulon managed these last few years is amazing. If you've never played rugby, or if you're an average player, you can't understand.

"But if you've played international level you understand just how difficult it is to win three years in a row quarter-finals, semi-finals and final -- nine matches in a competition like that, hats off."

As for O'Gara's own future, he's signed a three-year contract extension with Racing and has no intention of leaving the French capital before his work there has borne fruit.

"It was an easy choice because I couldn't leave here without having won anything.

"I have to win, find solutions for the team, there are no other options. Now I hope my hard work will pay off.

"This is perhaps the club with the most potential in Europe."

Having won the top prize in European club rugby twice as a player with Munster, O'Gara feels he has a lot to pass on to Racing's players.

"I'm proud of having played 10 semi-finals, four finals and twice won the European Cup. I know it's easy to talk now that I'm retired but I tell the players: prepare well, be demanding during the week because being a rugby player is a small window in your life.

"We have to make the most of this moment because it's the first semi-final in the club's history."
Source: AFP