The statement from the club comes after players in consecutive matches in the tournament's main stadium on Tuesday — Serena Williams and Adrian Mannarino — both slipped, hurt themselves and had to stop playing.
Mannarino's opponent, Roger Federer, said "it feels a tad more slippery, maybe, under the roof."
Wimbledon was canceled in 2020 because of the pandemic. The courts were removed and new grass installed, as happens after each tournament.
The club's statement said: "The preparation of the grass courts has been to exactly the same meticulous standard as in previous years."
The Centre Court has been roof closed "for long periods" due to showers on Days 1 and 2 this week, "at a time when the grass plant is at its most lush and green, which does result in additional moisture on what is a natural surface," the statement said, adding: "With each match that is played, the courts will continue to firm up."