Yes, there are players in the NFL who's first name starts with the letter V.
Some players are:
Ty CobbTom SeaverTony GwynnTed WilliamsTris Speaker
Xavier Adibi played tackle for Houston Texans 2008 - 2010 and for Minnesota Vikings in 2011.
Xavier Nady - OF for the Yankees.
luke horvacher, he is in the Royals organization
Andrey Ashavin (Arsenal), Anderson (Man United) to name but a few.