She made the announcement a week after losing the Wimbledon final to Czech compatriot Linda Noskova in a three-set thriller.
"I had to undergo a small surgery that will keep me off the court for a few weeks," said the 29-year-old.
"Everything went well, and I'm already working on my recovery," added Muchova, who also lost her other Grand Slam final at the 2023 French Open to Iga Swiatek.
Muchova, who has grappled with injuries particularly to her wrist throughout her career, hailed her good health en route to the Wimbledon final.
But now she said she would sit out the WTA tournament in Toronto on August 2nd-13th.
"Sad to be missing Toronto this year," the world number six said in an Instagram story against a backdrop of Britney Spears's "Oops!... I did it again".
"I was really looking forward to making my debut there, but recovery comes first," Muchova added.
She did not specify the injury nor the length of the recovery, or whether she expected to be fit for the US Open starting on August 30th.