Murray reached the second round at the U.S. Open this month in his first Grand Slam after hip surgery last year, but after developing a pelvic issue at Flushing Meadows the 33-year-old had to wait for a few days at home before meeting his doctor.
Kerber, a three-times Grand Slam champion who won the title at Flushing Meadows in 2016, converted four break points and has yet to drop a set at the tournament.
Nadal pulled out earlier this month due to novel coronavirus-related issues surrounding the August 31-September 13 tournament at Flushing Meadows, while Federer will miss the rest of the season after having knee surgery in June.
The Californian pair, famous for their trademark chest-bump celebration, had previously announced they would bid farewell after this year’s tournament at Flushing Meadows, scene of their Grand Slam debut in 1995.