Because somebody who insists on doing his own goddam stunts cut his forehead to the goddam BONE in a fight scene, to the tune of a severed muscle, bone bruise and 17 stitches. Back at work the next day, but damn, we've got to start putting padding around the set.
To be honest, it doesn't look all that bad. Because, of course, he decided to take the damn stitches out early. Himself.