Federer extended his lead over his great rival to four when he triumphed at last month’s Australian Open.
Nadal was on course to meet Federer in the final after sailing through the opening rounds but suffered a thigh injury in his quarter-final with Marin Cilic and was forced to retire.
If fully fit, Nadal would be favourite to win an 11th French Open title at Roland Garros and advance to 17 on the all-time list.
But Nadal insists he is not obsessed about catching Federer.
“It’s great to be ambitious, but not to excess,” Nadal said.
“You’ll go insane if you obsess on wanting more and more and more… the most important thing is to be happy with yourself.
“Of course, I do everything possible to win the maximum number of tournaments, but I’m not going to spend all my life thinking, ‘Federer has won more than me.’
“I just concentrate on what I can control and focus on that.”
Nadal is the current world No 1 but he could lose that next week after Federer announced he would play at the ABN AMRO World Tennis Tournament in Rotterdam.
Nadal holds a 155 point lead over Federer but if the Swiss reaches the semi-finals, he will overtake the Spaniard and become the oldest-ever men’s world No 1.