Paris - Former world No 1 Roger Federer is the only member of the 'big four' of tennis who has failed to enter next month's Monte Carlo Masters.
However, tournament director Zeljko Franulovic said on Thursday that the Swiss maestro could still make a late decision to play in the April 15-22 event.
Federer, now third in the rankings, clinched his sixth ATP World Tour crown in eight tournaments at last week's Indian Wells event in California.
World No 2 Rafael Nadal will be chasing his eighth Monte Carlo Masters title in a row and is joined in the lineup by top-ranked Novak Djokovic and No 4 Andy Murray.