The stakes are highest for Rafael Nadal in Monte Carlo

By Gerard Meagher, Sportsbeat

FOR the last five years in Monte Carlo, the city of high rollers, Rafael Nadal has held all the aces but the stakes have never been higher as the clay court colossus bids to make it six of the best.

WATERSHED MOMENT: Rafael Nadal will begin the clay court season with the watching world desperate to see if he can return to his best (Getty Images)

Nadal will arrive in Monaco for the start of the clay court season this weekend on the back of 13 tournaments without a trophy - a losing streak that would bankrupt even those with the deepest pockets.

The 24-year-old has been in decline since Robin Soderling unceremoniously sent him packing from his beloved Roland Garros last year and his weakened knees and bruised ego have yet to fully recover.

Nadal's knee problems have been well-documented. Tendinitis in both ensured the Spaniard could not defend his Wimbledon crown last summer while for the remainder of last season Nadal was effectively running on empty.

A winter break saw a leaner Nadal return to the court in 2010. The biceps were not as bulging and while he insisted otherwise, the mighty Majorcan did not pack as menacing a punch as he once did.

No doubt in a bid to alleviate the strain on his knees, Nadal was notably streamlined but as a side effect, did not strike fear into his opponents as he did when ruling the roost from August 2008 to last July.

Flashes of the form that saw him usurp Roger Federer as tennis' deity have been evident this season, but all too infrequent. His failure to win a trophy since last May demonstrates his decline into the mortal ranks.

And in his most recent grand slam appearance, Nadal was brought to his knees by eventual finalist Andy Murray at the Australian Open. The noises being made by Nadal remain positive however.

DOWN AND OUT: Rafael Nadal's knee troubles return as he loses to Andy Murray at the Australian Open earlier this year (Getty Images)

"I am playing well," said Nadal. "I had very good matches in these two tournaments in Miami and Indian Wells.

"I think I am ready to play my best. I'm just going to try my best in Monte Carlo now.

"Physically, I'm on good form. I no longer worry about my knee. I'm not scared of running hard. I think that my forehand is back to doing damage."

But the current world number three must act soon - Argentine powerhouse Juan Martin Del Potro and Murray to name just two - are threatening to exile Nadal from tennis' top table for good.

Nadal, however, will head to Monte Carlo hoping for a reversal of fortunes and the odds are favourable.

He has lifted the trophy on his last five visits to Monaco, has a total of 25 tournament victories on clay and until Soderling blew him off court last season has been invincible at the French Open since 2005.

Clay will also be kinder on his knees than the unforgiving hard courts which have hitherto been the ATP battlegrounds this season.

But Nadal is not the only one with something to prove in Monte Carlo. Murray began the clay court season last year riding the crest of a wave, having just won the Miami Masters but the Scot floundered in Florida this time around and was shown the door by Mardy Fish.

The world number four has never cut the mustard on clay but he arrives back in Europe only too aware he must arrest his recent woes and has tweaked his schedule to include a trip to Monaco.

Federer is the one big name conspicuous by his absence in Monte Carlo but the best of the rest will be throwing their hats into the ring.

As is his way, Nadal will compete at the other two clay-court 1000 Masters events in Rome and Madrid before resuming his love affair with Roland Garros in a shade over six weeks.

Conquering all will not be Nadal's number one priority but getting his hands back on the Coupe des Mousquetaires will be and whether he does or not will say a great deal about whether the Spaniard's recent decline is terminal.

The eyes of the watching world will therefore be on Nadal in Monte Carlo, desperate to see if clay can catalyse him back to his best.

It is not yet the last throw of the dice for Nadal in Monte Carlo but the Spaniard will arrive in Monaco as the one with the most to lose.