Tim Henman says Andy Murray must be completely fit to challenge for the US Open following his injury problems this year.
The world No 1 has struggled in 2017 so far, making it to just the fourth round of the Australian Open, the semi-finals of the French and the quarter-finals of Wimbledon.
Murray is set to lose his spot at the top of the rankings in the coming weeks and failure to make it to the final of the US Open would make it just the second year since 2009 that he hasn't managed to reach the final day of a major.
"He's got to be fit and healthy," said Henman. "The standard is so good you can't compete unless you're 100 per cent healthy so it will be interesting to see what his schedule is in the summer and in the lead up to the US Open, but hopefully he can regain that fitness and start challenging for the biggest titles again."
There's been plenty of talk in recent weeks about the benefits of extended breaks after Federer's stunningly successful 2017 so far, but Henman believes it's not worth taking a long rest unless it's absolutely necessary.
"No, you're not going to take a break for the hell of it," he said. "Federer needed to take that break because he'd had a knee operation and his knee wasn't right.
"At the end of the day the most important thing is your health and, as I said, you can't compete at the top of the game unless you're 100 per cent healthy or extremely close to it.
"Murray's had problems with his hip. I know that he's having a lot of tests at the moment and scans and seeing specialists to try and get to the bottom of that. And hopefully he can be back competing soon."
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