Andy Murray says his preparations for the French Open were slightly delayed because of a "five or six-day wait" for his coronavirus test result.

A scan later showed tendonitis of the psoas, the muscle which joins the lower back to the top of the leg.

"We had to get a test when we got back from New York and test negative before we could leave the house," said Murray.

"There was a bit of an issue with my test. It took five or six days to come back, so in was my house for five or six days and I couldn't get that checked out."

Other than having to adjust his training slightly, former world number one Murray says there have been no further problems before his first-round match in Paris against Stan Wawrinka.

"Once I started practising on the clay, I actually felt pretty good. I've been playing, I think, quite well," said the Scot.

"Usually, it feels like it takes quite a long time to get used to the surface again, and it didn't feel like it had been three and a bit years since I had last played on it. It was better than what I expected."

Murray has had another Covid-19 test since arriving at Roland Garros - and, in his experience, the nasal swab testing at the French Open is more invasive than it was at the US Open.

"They get right up there," he added.

"I know that's what's supposed to happen, but it's just weird. I've never had that before when something goes up through your nose and into your throat.

"Testing is definitely more uncomfortable."