Where it was positioned...non throwing throwing wrist/forearm (easily accessible by the pitching hand) and only about 2'' x 1'' spread, there is no doubt it was intentional. No way that he was using it for any other reason than an advantage while griping and delivering the baseball. It wasn't there because it was sheltering that small section of arm from the sun/wind. Whether he uses it during warmups and truly forgot to wipe it off, I'm doubtful. These are professional athletes. I'm an amatuer golfer, but I don't forget to take a penalty stroke when I hit a ball in the water....you think he "forgot" to clean an illegal substance off his arm before going in the game? If the substance was part of his routine in the bullpen, did it suddenly stop becoming part of his routine once warming up the mound? No way. It's rosin. The same thing that you can get from the bag behind the mound. When you're warming up in the bullpen it makes perfect sense (when how quickly you can warm up is an issue) to dab a bit on your arm so you don't have to walk over, grab the bag, shake it on your hand between pitches. Just a quick touch and go to the next pitch.