By Toby Cudworth Kylian Mbappe may be prevented from wearing a protective mask that he’s had on in France training because of a little-known Uefa rule. Mbappe broke his nose in France’s opening Euro 2024 clash with Austria following a nasty coming together with opposition centre-back Kevin Danso. The 25-year-old leapt to win a header as the ball was crossed into the box, only to be intercepted by the point of the Austrian’s shoulder. Extensive on the field treatment was required before Mbappe could be taken off, with Real Madrid’s new talisman looking to be in extreme discomfort. France commun…