The team said it unintentionally committed the violation and that Owens should have just been in a shell and not shoulder pads during his debut practice on Wednesday.
League spokesman Greg Aiello said in an email that the league is gathering facts. The Fort Worth Star-Telegram first reported the possible violation.
The CBA states that players have a three-day acclimation period during the preseason after signing: "Day 1 is for the physical and meetings. Day 2 and 3 the player may participate, but only in helmet and shells or a padded shirt. Day 4 and for the rest of camp is in full pads."
Owens signed Monday, making it his first day. He attended meetings and a walk-through on Tuesday and was in full pads for Wednesday's practice.
It's unclear if the team will face any discipline.