Andy Roddick revealed Saturday that he should pull up fit for for the Cincinnati Masters starting Sunday after beating a mild case of glandular fever.
The American, his ranking now down to 11th, said that he skipped this week's Masters 1000 in Toronto on doctor's orders, adding that his fitness is back after an enforced week of rest.
"I got some blood work done in Washington (his previous event), and then again in Texas, and one of them came back positive. I guess I've been dealing with a mild mono for the last couple of months that I wasn't really sure about," said the former number one, a three-time winner of the event.
"They think I'm fine now, they think I'm most of the way through it, if not all the way through it. It's a mental relief opposed to wondering why, if I was out of shape, this that, and the other."
Roddick won two titles early in the season, including the Miami Masters, but has tailed off in recent months. He went out in the Wimbledon fourth round after playing three finals at the All England club, including 2009.
"I'm through the worst of it, which is good," he said of his medical problem. "There were some days where it was good and some days where it was real bad.
"It's nice to just have a little bit of clarity moving forward. It was good to at least figure it out, and well worth my time."
Roddick said he had been suffering with sub-par feelings for several months before doctors finally figured out his problem. "That wasn't fun. It was just me wondering if I was out of shape or what was going on, why there was this lethargic feeling.
"I'm feeling better, the good news is you're probably ready to rock. (The doctors told me): 'Be a little careful, you should be fine to go'. So that was a relief."
Roddick, seeded ninth in the last major tune-up prior to the August 30 start of the US Open, begins in the first round with Sergiy Stakhovsky of the Ukraine.