Federer, who has been struggling to overcome a back injury in recent weeks, admitted, "I'm happy I was able to play and still feel about the same, like yesterday [versus Alexander Zverev], not worse. That was most important. The next 10, 12 days are really going to be important for me to recover, and then make a plan.
"I'm confident and hopeful at the same time. I have only played five matches in the last four months now, so clearly I don't want to get too overly excited about what's ahead, but at the same time I'm a positive thinker and I believe that I'm going to recover.
"Hopefully, the next 10 days are going to be easier and I can practise really well, sort of starting next week. That's the hope I have and then we'll see the rest, how it's going to come."
Federer, who had practised on clay in Miami and for 10 days in the build-up to last month's Monte-Carlo Rolex Masters, is not concerned that he lacks matches. "I [have] never had better clay-court preparation, to be honest," said Federer. "I have a lot of hours on the clay already this year. Maybe not on match courts but on practice courts.
"I actually thought I could really do a good result in Paris. Now the past couple of weeks it's been more difficult. I see my chances as not great to have the most unbelievable run, but if maybe in three, four days I can practise 100 per cent for the next week, then I believe that something is possible again.
"Clearly, the way I'm playing right now is never going to be enough for any good run in Paris, and then I also wouldn't play this way. I'm still confident I will be fine somehow."
Federer will enter the second Grand Slam championship of the year, which begins on 22 May, with an 11-4 record on the season. Federer remains two match wins (1,070) away from moving past Ivan Lendl to No. 2 in the Open Era list for most victories. Jimmy Connors leads with 1,256 match wins.