Andy Murray was ruled out of the Cincinnati Open late on Monday as he recovers from an abdominal strain.
The Briton wants to participate in the US Open, final grand slam of the year, which begins later this month.
The 36-year-old also pulled out from last week's Canadian Open before his last 16 clash with eventual champion Jannik Sinner due to the issue he picked up after spending nearly five hours on court in matches against Lorenzo Sonego and Max Purcell.
According to men's tennis governing body ATP, the three-time Grand Slam champion will be replaced by a lucky loser at the Cincinnati Open.
The former world number was set to face Russian 11th seed Karen Khachanov in the first round of the event.
Murray is ranked 36 in the world — his best ranking since hip resurfacing surgery in 2019 — and was included in Britain's Davis Cup team for their Finals group stage ties that will be held after the US Open.
It must be noted that the US Open is set to take place from August 28 to September 10 at the Flushing Meadows.
Earlier, Murray stated that he still feels like a “top 10” player in the world on grass.
“It is hard to put numbers on it like that but yes, I would fancy myself against a lot of them,” Murray replied when asked if he still considers himself a top 10 player in the world on grass. “Last year I won against [Nick] Kyrgios who made the final of Wimbledon. I won against [Stefanos] Tsitsipas – it is probably not his favourite surface but he is one of the best players in the world.”
Murray also admitted that he believes that he is playing better than last year.
“And I’m playing better this year than I was last year. But it is kind of irrelevant if you say that. You have to perform and win the matches on the court and it is up to me to show that in the next four or five weeks.”