Greg Hardy's appeal of his 10-game suspension before arbitrator Harold Henderson ended after about seven hours Thursday, with Henderson not giving an indication of when he will deliver a decision, sources told ESPN's Andrew Brandt.

While his Dallas Cowboys teammates are concluding the first week of organized team activities at Valley Ranch, the defensive end was expected to be in Washington, D.C., for the appeal.

The appeal for Greg Hardy, seen here in February, ended Thursday with no timetable for a decision. AP Photo/Chris Keane

Hardy, who signed with the Cowboys this offseason, missed all but one game with the Carolina Panthers in 2014 because of a domestic violence issue and subsequently was suspended 10 games this season by the league for violating the NFL's personal conduct policy. He remains on the commissioner's exempt list.

Hardy was initially found guilty of assaulting a female and communicating threats by a North Carolina judge, but the charges were dismissed when the accuser did not make herself available for a jury trial. Hardy has since asked for his record to be expunged and has relinquished his weapons to the Mecklenburg County Sheriff's Office as part of the bond requirements in the case.

Henderson, a former NFL executive, was picked by the league to hear Hardy's suspension appeal. Henderson denied the appeal of running back Adrian Peterson, which was later vacated by Judge David Doty. Peterson has since been reinstated by the league but the NFL Players Association wants the NFL, the management council and commissioner Roger Goodell held in contempt of court since Henderson has issued a new ruling on Peterson's case.

At the heart of Peterson's defense was the fact that the NFLPA felt the NFL punished him under the league's new personal conduct policy despite actions that occurred before it was adopted.

That will be at the heart of Hardy's defense as well.

After conducting an investigation of its own, the NFL suspended Hardy for 10 games because of at least four instances of physical contact with his former girlfriend, Nicole Holder.

In an email, the NFLPA said the 10-game suspension was "totally unprecedented under the policy that was in effect at time of alleged conduct."

The NFLPA believes the league's mention of guns being involved in the incident is a sign the league applied the new personal conduct policy since guns are not mentioned in the league's old policy.

Henderson took roughly a week to make a ruling in the Peterson case and could use a similar time frame in the Hardy case. If the appeal is not granted, the NFLPA would almost assuredly take the case to court.

ESPN Cowboys reporter Todd Archer contributed to this report.