Lions rookie holds his own against Giants' mammoth first rounder

The Detroit Lions and New York Giants just had one of the chippiest joint practices of all time. It almost felt like a fight club meeting or that scene from Anchorman where all the news teams fight. Nobody was stabbed with a trident on Monday though.

One of the big things that happened was that Lions' cornerback and first round pick Terrion Arnold left practice early and is being evaluated for a concussion after taking this hit from Giant tackle Andrew Thomas.

Anyone notice anything there? Besides Arnold doing a good job of absorbing the hit and staying on his feet. Take a look at everyone's head and then look at Thomas'. He's not wearing his guardian cap on his helmet.

The guardian cap is requirerd to be worn by all players who aren't quarterbacks, punters or kickers during every single practice per the NFL , but there are helmets that test out better than the guardian cap and Thomas was wearing one of them.

So no rules were broken by the Giants. We'll see soon what Arnold's status is. But man he sure looked like a grown man out there Monday.

Related: 4 potential Giants' cuts that the Lions could be interested in