Dr. Sharif Ellozy, a vascular expert and associate professor of surgery at The Mount Sinai Hospital, offers these insights on Dillon Gee's blood clot:

If it reaches the severity in the shoulder to where a catheter needs to be used to break up a clot, how significant is that and what risks were there before the procedure?

"It sounds like he had a clot in his artery and some numbness in the hand. Basically, your blood flow to the arm is limited. So depending how severe the blockage is, it can range from having some mild numbness to the arm being at risk. It sounds like it was mild in that he just had numbness. Obviously he needs the blood flow to his hand to be able to pitch, so it's something that needs to be treated relatively urgently."

If it had been undetected or untreated, what were the most severe risks? A clot can move into a spot where you don't want it and potentially be fatal?

"Probably not fatal. But, you can have permanent neurological function dysfunction in the arm if it goes too long before being fixed."

What does a procedure involving a catheter to break up a clot entail?

"So they place a small tube over a wire into the artery, directly into the clot. And then you can use different mechanisms. You can give medication that chews up the clot. You can balloon it. There are a number of different things you can do over the catheter. You don't have to open up the artery. You can go through a puncture in the groin."

In terms of a professional athlete, if he needs to get back to pitching, assuming the danger is passed, what's the idle time?

"They're going to have to anti-coagulate him for at least a little bit. You can get up and start moving within a day or so. As far as him going back to pitching, it depends on what the artery looks like -- if the artery looks normal or if they think there's some abnormality in the artery that caused it. The fact that he's a pitcher and that it was in the arm that he was pitching from, you suspect there may be some injury where it goes between the clavicle and the first rib in that arm. How soon he'll be able to return depends on what they find."