The 32-year-old lost a tight contest to Urszula Radwanska 6-7 7-6 4-6 on the opening day of the tournament in just over three hours.
Speaking after the match, in which her first-serve average speed was well down at around 95mph, Venus said she was looking to recover from a back problem in time for Wimbledon.
“I can’t really serve very hard. It’s painful when I do that,” Venus reflected.
“But I’m getting better. I just ran out of time to get better for this tournament. My strategy was more or less to put the ball in, and that’s very difficult for me, too, because that’s not who I am. But that’s all I had…I want my serve back. I’m going to try to get it back for Wimbledon.”
Venus is still penned in to play doubles with her sister Serena at Roland Garros.
“As long as I serve soft, I don’t think I’ll get worse,” she said. “I think my opponents like the soft serve.
"I don’t think I’m just playing for me now. I think I’m playing for a lot of people who haven’t felt well. I think for me today it’s a positive to be able to play three hours. I’m constantly finding ways to get better and to feel better.”