Scotland's Jamie Baker may have risen to become Britain's No.2 player behind Andy Murray this week, but the achievement has a hollow ring for the Glaswegian after he was diagnosed with a potentially life-threatening virus.

The progress of the 21-year-old up the rankings came to a sudden halt at the end of last month when, while training in Florida, he discovered unexplained bruises on his arms, a rash on a shoulder and saw blood on his handkerchief having blown his nose.

Unbeknown to Baker, those apparently innocuous symptoms were signs that he was probably suffering from the virus, ITP, Immune Thrombocytopenic Purpura, which had caused the platelet level in his blood to fall to such a "catastrophically low" level that he ran the risk of bleeding internally.

Fortunately for Baker, his practice partner Brendan Evans' mother is a nurse and spotted straight away that the Scot was in grave danger. She ordered him to the emergency room at the nearby St Joseph's Hospital in Tampa, where Baker spent three days in intensive care having been told that even the smallest bump or graze could have caused him to bleed to death.

The good news is that the Scot is now feeling fine and is expected to make a full recovery from his illness. He is back at his UK training base in Loughborough, where he is undergoing a course of steroids, the dosage of which is being gradually tapered down.

He is now taking only half the amount of medicine he was four weeks ago and has even begun taking gentle exercise, albeit only every other day and under the strict supervision of the Scottish Institute of Sport.

It is likely to be months before Baker can start playing competitive tennis again, though, and he is very unlikely to be fit in time to play at Wimbledon.

It is particularly cruel that Baker, renowned as one of the hardest-working players in the British system, has suffered such misfortune at a time when his career was in the ascendancy. He reached a career-high ranking of 211 in November, qualified for the Australian Open in January and acquitted himself well after having made the team for Great Britain's Davis Cup tie against Argentina in Buenos Aires in February.

Now the hard work must start all over again, although his friends and colleagues in Scottish tennis have no doubt that Baker has the gumption to battle his way back to full, competitive fitness.

Judy Murray, who has nurtured Baker's career since he was a youngster, believes that his experiences of overcoming a serious knee injury when he was 14 will stand him in good stead.

"He's a strong willed enough character to be able to see this through and he's also very practical - he'll follow everything to the letter and do exactly what he needs to do to get better," said Murray, a former head coach at the Scottish Lawn Tennis Association.

"I think the fact that he's been through a similar experience before when he was in his early teens means he's well equipped to deal with the situation. He's so professional in his approach to everything to do with his tennis and that will really help him."

Her son, Andy Murray, was also concerned to hear about Baker's health troubles. "It's a tough one because from what I heard, only 66 out of a million people get the virus and it's surprising that he picked it up," said Andy Murray. "However, I'm sure he'll manage to get through it. He's strong mentally and loves tennis enough to get himself back fit and healthy."

Baker's career might have suffered a significant setback, but, however many difficult months of rest and rehabilitation he has ahead of him, he also has many reasons to be thankful.

"I think he feels quite fortunate really to still be alive," said Jamie Murray, who has been on the phone to Baker to offer his good wishes.

"It seems weird to be saying sort of those things. I mean, he's an athlete. He's healthy. He takes care of himself and, bang, he could have died."