Boris Becker believes Andy Murray might be better off pulling out of the French Open to let his back problem recover in time for Wimbledon and the Olympics.
Murray was clearly troubled by the injury as he lost to Richard Gasquet in Rome last week, revealing afterwards he had been carrying the complaint since December.
"I worry where Andy is physically," Becker told The Daily Telegraph.
"Back pain is a disaster on clay. On any other surface you can handle it because you can finish matches quickly, but on clay you have to be ready to play for two or three hours every day.
"We saw Andy couldn't handle that in Rome.
"I'm not a doctor, but if he's not fit, the question must be: 'Why play at all?'
"Nobody can win seven matches over the next fortnight without being in decent physical condition, not even Rafael Nadal.
"So if he has no realistic chance of winning a grand slam title, why not get some rest?
"With Wimbledon and the Olympics coming up, that is two big reasons for Andy to think about his long-term health."