The NFLPA would argue that the rule violates the "working conditions" specified by the collective bargaining agreement, a source told Marvez. The union would file a grievance claiming that the rule could only be implemented via a side-letter agreement to the CBA.
A source told Marvez that the league has not provided proof to the NFLPA that the pads would have any effect on player safety, though the union has asked for it.
Marvez reported that another possible issue, which we touched upon earlier Monday, is that players will resist being forced to wear leg padding out of vanity or concern that the padding will negatively affect their ability to perform -- even if the intended goal of requiring pads is to keep the player on the football field.
"Guys want to feel as sleek as possible," NFLPA President Domonique Foxworth told FOXSports.com last year. "Anything that inhibits that makes them feel it's slowing them down or getting in their way. Some guys have never played with those pads. It's difficult for them to wrap their heads around it mentally."