Andy Murray has withdrawn from the Miami Open because of a groin problem.
The British two-time winner, 33, had been awarded a wildcard and was set to play South African Lloyd Harris in the first round of the tournament, which starts on Wednesday.
The world 118 said that he "struggled to walk" after developing pain while sleeping on Friday.
The three-time major winner was ranked second in the world when he last competed in Miami in 2016.
"I had no issues while training, felt fine, did some gym work Friday, no problem," Murray told the Miami Herald.
"I woke up about three in the morning, felt pain in the groin, not on the side I had my surgery, got out of bed I struggled quite a bit to walk."
Earlier this month, the Scot was knocked out in the second round of the Rotterdam Open by world number eight Andrey Rublev having also received a wildcard for that event.