Andy Murray will test his troublesome elbow at the Monte Carlo Masters this week. Photo: Michael Buholzer, AFP

Andy Murray admits that he will only find out the state of his injured right elbow when he steps on to the clay of the Monte Carlo Masters this week and fires his first serve.

The World No 1 begins play in the second round on Tuesday or Wednesday after a bye, against either Tommy Robredo or Gilles Muller, as he bids to regain full fitness after the injury that forced him out of the Miami Open a month ago.

“I was not optimistic after playing Roger (Federer) in Zurich (exhibition last week), my serve felt much slower than normal,” the Scot said on Sunday.

“But every day I was building up. Often the elbow can get sore if I’ve not served for a week or 10 days. But each day started to get better.

“That’s what we had been hoping for. I had to take two or two-and-a-half weeks off for it, so I don’t know which it was, the lack of serving or the injury.”

The 29-year-old said that Monte Carlo will be a good test of his fitness.

“I would not be playing if I felt I was taking a risk. For the last two days, I’ve been serving normally,” he added.

“By the time of my match, I will have had five days of serving at the right speed.”

Murray, who has endured a mixed start to 2017 after soaring to the top of the world rankings in November, said that his elbow problem might have stemmed from the big push he made to reach the top of the rankings.

“But I feel fine now, even if the start of the year was a bit tough. I’ve been lucky with injuries,” he said.

“I have a lot of big events coming on, and I’m looking forward to them. My clay expectations are very high.”