49ers star Dre Greenlaw banned for one game after vicious headbutt on Seahawks rival

San Francisco 49ers star Dre Greenlaw has been punished by the NFL for his shocking headbutt on his opponent during Sunday's game. Greenlaw was ejected from the 49ers showdown against the Seattle Seahawks after he delivered a headbutt to the unprotected head of Ernest Jones IV on the sidelines during the second quarter of the Week 5 win for San Francisco. The Niners will now be without their No. 2 linebacker once again with Greenlaw hit with a one-game suspension for the 'unsportsmanlike conduct.' The ban, which was announced by the league on Monday afternoon, will see Greenlaw miss the…