World number one Novak Djokovic admitted on Sunday that he cannot guarantee he'll start the Monte Carlo Masters as he battles the after effects of an ankle injury.
"I can't guarantee 100 percent that I'll be on court. I have to be realistic and cautious," said the world number one who rolled his right ankle badly a week ago during Serbia's Davis Cup win in the United States.
"I've had three days of practice and I've been increasing the level each day.
"If I have discomfort over the next two days that would be an indication if I should or should not play."
Djokovic, who is based in Monte Carlo and feels a responsibility to compete if possible in his "home" event, said that he will make a final decision by Tuesday.
He and the other top eight seeds all received byes into the second round.
"This is a strong event and there is no room for compromise," added the Australian Open champion.
"This is the start of a new season on a new surface. To compete at a high level I must be 100 percent fit.
"I've been taping the ankle and doing all I can to be ready on the court. I know there is a lot of expectation for me to play - no one wants me to be out there more than I do. I consider this a very special place and I'm extra-motivated.
"I'm really encouraged by the progress over the last few days, it's much more than I would have expected it to be. I'll do everything in my power to play."
Meanwhile, Bernard Tomic's European claycourt season got off to the worst possible start as the Australian went down 6-2, 6-4 to Alexandr Dolgopolov in the first round on Sunday.
Tomic, who now has a base in the tax-free principality, failed to shine in his new locale, losing in one hour to the 22nd-ranked Ukrainian who has now won four of their five career meetings.
The result was a repeat of the defeat Tomic suffered to the same player in the same tournament a year ago in the second round.
The 43rd-ranked Queenslander was broken three times in the brief affair which marked his ATP spring introduction to the clay after winning both of his Davis Cup ties on the surface in Uzbekistan last weekend.
The Australian's loss was his seventh of the season against 13 wins; he now stands 1-3 in Monte Carlo.
With leading seeds given first-round byes at the cliffside Monte Carlo Country Club, only three main draw matches were scheduled on Sunday.
German Philipp Kohlschreiber, a two-time quarter-finalist, became the first seed into the second round as the number 16 dispatched Thomaz Bellucci of Brazil 6-4, 6-2.
Highly-regarded Grigor Dimitrov of Bulgaria also made it through with a 6-3, 6-2 win over Belgium's Xavier Malisse.
As well as Djokovic, all eyes at the tournament will be on third seed Rafael Nadal who is bidding for an unprecedented ninth straight trophy at the event.
Britain's Andy Murray, the Miami champion a fortnight ago, takes the second seeding and could line up against Nadal in a possible semi-final.
World number two Murray is in some danger, however, with calculations suggesting that if he loses before the quarter-finals, his place in the rankings will be retaken by Roger Federer.
The Swiss, currently third in the world , is missing the only optional Masters to continue a pre-planned training block in his native Switzerland.
His return is set for the Madrid Masters in three weeks, where he will be defending his 2012 title won on controversial blue clay.
Spanish grinder David Ferrer, the losing finalist in Miami to Murray and the 2011 runner-up to Nadal in Monte Carlo, withdrew before the start with a thigh injury.