Former world number four Robin Soderling is eager for another crack at life on the ATP Tour but admits he may not win his battle with mononucleosis.
The viral infection has sidelined the Swede since the summer of 2011, halting a career which had seen him reach two French Open finals.
The nature of the illness means he has good and bad days, which he concedes is hard to live with.
He told ESPN: "The hope, the hopelessness, then the hope again, then the hopelessness - that really kills me.
"I feel really good, then I start to practice, and then I think maybe in a couple of months I can come back and I really believe it.
"Then I do a bit too much and wake up one morning not feeling well again."
He added: "In the past couple of months I had my best weeks and days, which gives me the hope, but I get setbacks and feel worse again.
"Overall it's getting better but I'm not as desperate to come back any more tomorrow. I will give it a shot, of course, but I learned to live with the thought that maybe it will not be possible.
"Whatever happens, I will feel I did all I could."
"The hope, the hopelessness, then the hope again, then the hopelessness - that really kills me" - Robin Soderling on his struggle with mono
Soderling, 28, has recently become a father and that has helped put his current struggles into perspective.
"For the first time in my life I'm not putting myself first, which is a very strange feeling," he said.
"It's also nice. All my life I've been focusing on tennis, training, getting results.
"I feel I have at least five more years in me. But I still have a lot of things to be thankful for. The (mono) could have happened when I was 18 or 20. I was 27. Up to now I've had a good career."