(Thanks for the shout-out, BTW.) The simplest example of a hematoma is the “blood blister” you get under a fingernail if you hit yourself with a hammer. This is obviously a very finite, small example, but it certainly does feel better when drained. Given that Valverde is young and seemingly healthy, he will likely have a quick recovery. There are a couple of things that concern me; first, we don’t know what the specific injury is that caused the hematoma. We surmise that it was trauma to a blood vessel caused by the impact of the ball, and this would be best-case, IMHO. By the time they drain it, the vessel itself will have started to heal, and the issue won’t likely occur. However, I’ve seen hematomas caused by muscle tears themselves—and that would open a whole new can of worms, as you might imagine. One would hope they would have picked that up on the MRI, but it’s possible that there is enough tissue distortion for it to be missed until after the fluid is drained. A serious enough tear to cause a hematoma would probably put him out for a good part of the season. Secondly, there is always a chance of infection. This is usually a minimal risk in someone Valverde’s age and health status, but blood is an excellent culture medium (remember blood agar plates from microbiology?), and certainly baseball clubhouses have their share of contagion. Didn’t some AL club (Baltimore? Cleveland?) have some problem with MRSA a year or two ago? Too lazy to look it up.