It's no tattoo, obviously. Just the best hair line in this squad.
It's obvious he's high on testosterone. Traditional alpha male behaviour, probably very competitive and wants to win.
Unlike Koop, who's low on testosterone and his hair line is receding rapidly. Steroids at Atalanta took its toll in the long term.
He's also no midget as the photo's might suggest, stands tall at 1.80 (which is +20 cm larger than Chico). I don't think he'll be pushed off the ball as easily as Chico.