Three years ago it was discovered I had a DVT clot in my leg, that spread to my lungs causing a pulmonary embolism. After six months on Xarelto (blood thinner) I was cleared to play sports, and have had no problems since then. I don't even have to take aspirin now.
In my case, I think the original clot was caused by a leg injury followed by a long flight. Hopefully, it was related to that one incident, and I'm not predisposed to clots in general. I hope Stone has a similar outcome, and can resume his career with no concerns.
https://www.webmd.com/dvt/blood-clot...r-leg-injury#1
http://www.hematology.org/Patients/Clots/Travel.aspx