Mallorca, August 30: Andy Murray said he was suffering from cramp and fatigue following his last-16 loss to world number 240 Matteo Viola at the Rafa Nadal Open.
Former world number one and three-time grand slam champion Murray struggled physically as he went down 3-6 6-4 7-6 (7-3) at the ATP Challenger event in Mallorca on Thursday (August 29).
Murray dropped down to the Challenger Tour for the first time since 2005 in a bid to improve his fitness following hip resurfacing surgery in January, which threatened to end his stellar career.
After blitzing teenager Imran Sibille and overcoming third seed Norbert Gombos, the 32-year-old Murray succumbed to Viola in a third-set tie-break.
"I'm cramping. Very tired," said Murray, who required a medical timeout midway through the third set, after almost three hours on court.
"I would have liked to have played more matches but it was good. I played two competitive matches. Physically I need to get better."
Murray is featuring on the Challenger Tour for the first time in 14 years.
The Brit started a singles comeback at ATP Masters 1000 tournament the Western & Southern Open before making a swift exit from the Winston-Salem Open.
Murray – who played a series of high-profile doubles tournaments after teaming up with Serena Williams in the mixed event at Wimbledon – then opted to skip the US Open in New York.