Not a Good Place to be Bleeding

In the first leg of Villareal and FC Internazionale, Inter won 2-1. The game itself wasn't very impressive but there was an odd occurrence with one of the Villareal players. Marcos Senna, a midfielder, appeared to be bleeding from his crotch area. The entire inseam of his yellow shorts had turned red. I'm not a medical expert but that doesn't sound like a good thing. I can't find a picture yet, but the one on the right is a fair recreation of the actual image.