This all seems shady as hell. I know I wouldn't want Kyrie to play with a concussion, even in the finals. The next decade is more important than a single game.
That said, didn't Klay get 3 stitches in his ear? Sounds like a cut to me. Not saying all the blood is ear blood, but that certainly explains it. Hopefully we get the truth about this. Honestly, if he is concussed, and plays, the Cavs might actually benefit from it. Klay's main value is as a shooter, but with a concussion, i'd take my chances on him, and put Kyrie on him.