Swiatek 'plays it safe' with Rome retirement ahead of French Open defence
Top seed and two-time defending champion in Rome, Swiatek was tied 2-2 with Elena Rybakina in the deciding set on Wednesday when she decided she could not continue.
The Pole had attempted to carry on playing with her leg strapped up after a medical timeout but said she felt pain while stretching on court.
"For me, the most important thing is to kind of play it safe and not exploit my body so much in such a difficult conditions, after having to play few matches in night session and after midnight," Swiatek said in a statement on Thursday.
"To be ready for Roland Garros I need to recover right now. I'm going to take a couple of days off. With my quarter-final loss, I have also time to then practice right before the tournament.
"I'm happy right now to have few days off because since Stuttgart I wasn't really able to recover with that tight schedule that we have on the WTA."
Swiatek won the Stuttgart Open in April when she beat world number two Aryna Sabalenka. The Belarusian got her revenge in the Madrid final earlier this month.
The French Open runs from May 28 to June 11.