The British three-time grand slam winner - inlucidng the 2012 US Open - was forced to withdraw from this year's warm-up tournaments in Toronto and Cincinnati.

The 36-year-old was unable to serve in practice until this week due to what he revealed turned out to be a torn abdominal muscle.

"The first five or six days were a bit complicated. There were lots of different opinions," said the Scot.

"It is quite a difficult place to scan, the ab, so we weren't really sure the first few days. And then I came to New York pretty early and went to one of the hospitals here and had the radiologist from back home who looks at my scans check them.

"I had a small tear, which is healing. And the last five or six days of practice have been really good. I have not had any issues serving.

"It is just obviously that you don't take a week off from serving then go full into it. You need to build up a little bit. It has not been perfect in that sense but my ab has been OK."

Murray begins his latest New York campaign against Corentin Moutet, the world number 71 from France, on Tuesday.

If he comes through that, a tasty second-round meeting with Bulgaria's 19th seed Grigor Dimitrov is on the cards.