That is what happened in February when Coleman was struck down by blood clots in his legs for the second time in his career.
The first time was far more serious when as a 23-year-old he was just making his mark and his career almost came to a thundering halt. But he almost lost so much more.
"Back then I had it really bad and they thought I might lose my leg," remembers Coleman.
"It is because I have a condition called ulcerative colitis, which is where all the problems started."
Ulcerative colitis is a form of inflammatory bowel disease, similar in some way to Crohn's disease, with 15,000 New Zealanders believed to suffer from one of the two.
Since his first diagnosis and the horror of nearly losing his leg 26 years ago Coleman has managed the condition, most importantly by watching what he eats. But a course of antibiotics he took pre-Christmas is believed to have made his condition flare up and resulted in the February blood clots.
"I was in hospital for six days and the doctors there gave me some blood thinners thinking I could just stop taking them when I was riding, but I don't think they realised we ride all the time.
"And they were too dangerous to ride on in case I had a fall. On the blood thinners the chances of internal bleeding, especially if I suffered a head injury, are too great.
"So when I was told that I went home and packed up my riding gear and put it away. I thought I was done."
But a visit to a Hamilton hematologist who researched a different medication that could stop clots but still allow Coleman to ride saved his career for the second time.
"We have spoken to the NZTR doctor and had it all cleared and I had a couple of trials rides at Cambridge on Tuesday," says Coleman. "I had a bit of a blow after but my fitness isn't too bad and I am walking 55kgs so that gives me plenty of options."
One of those options is class filly Media Sensation, who is likely to return in the open sprint at Ellerslie on Saturday as a lead up to the Cambridge Breeders Stakes and a possible Queensland campaign.
"It will be great to be back riding but particularly a filly like her if she starts. I still love riding but riding the good horses, that is where the real buzz is."
Coleman won the 1000 Guineas on Media Sensation in November, continuing a remarkable record of having ridden at least one group one winner every year for the last 20. They make up part of his 39 career group ones, with 186 group and listed wins in New Zealand.
Coleman resumes on Saturday just six wins short of 2100 domestic victories, "with about 50 more overseas, mainly Australia".
But as much as he is looking forward to getting back to work, on a real racehorse, doing the thing he was born to do, Coleman admits there is something he missed just as much during his enforced layoff.
"I love the chat, the smack talking that goes on in the jockeys' room," he laughs.
"We all get on pretty well but we still give each other a hard time and you miss that when you are away from it.
"That and riding winners. The thrill of riding winners never gets old."
Return of the king
• Michael Coleman, nicknamed The King, returns to riding at Ellerslie on Saturday.
• His career was threatened for the second time last month when he suffered from blood clots in his legs
• One of New Zealand's most successful ever jockeys, Coleman is closing in on 2100 domestic wins.
• He has seven rides including his 1000 Guineas winner Media Sensation.
