Horner crashed out of this year's Tour de France on stage seven, suffering from concussion, a broken nose, a fractured rib, and injures to a leg and ankle. He returned to the US in order to recover and had even begun training for the Tour of Utah and the USA Pro Cycling Challenge in Colorado. However the blood clot has caused him further problems.
"I started having a sharp pain in my side. I initially thought it was cramping caused by the rib I had fractured in the Tour crash. However, it kept getting worse, so I called my favorite local orthopedic doctor, Dr. Gingold, for a little advice, and he told me to head straight to the hospital," he posted on his blog.
"On the way, I started to have some serious pain - some of the worst pain I have ever had in my life, which is saying something! When I got to the emergency room, Dr. Gingold had already called ahead, so I was escorted straight in for tests. Turns out, I have an updated injury list from the Tour crash – a broken nose, a fractured rib, something wrong with my calf and ankle, a splitting headache, and … a blood clot in my lung. And no, that’s never a good thing!"
Horner will undergo blood thinning treatment as well as undergo a series of additional tests.