The NFL rejected a petition by Dallas Cowboys to wear a helmet decal showing support of the Dallas Police Department during preseason games.

According to team vice president Stephen Jones, the league had already vetoed the team wearing the decal in regular season. The preseason ban is new.

The Arm in Arm decal was unveiled during a ceremony on the first day of Cowboys training camp, meant to be a sign of support and unity for both the Dallas police and the city following the fatal shootings of five police officers last month.

Jones said the team respects the NFL's decision.

Tight end Jason Witten had come up with the idea.

(h/t Fort Worth Star-Telegram)