7:47 PM ET

The Cowboys said in a statement that former Dallas Cowboys and Chicago Bears running backMarion Barber III died at the age of 38.

The team said they were devastated by the death of a hard-nosed football player. He loved his coaches and teammates and had a passion for the game. Our hearts go out to the family and friends of Marion.

The cause of death is not known. Police in Texas responded to a welfare concern at an apartment they believed to be leased by Barber. The police said they were investigating an unattended death at the location, but didn't identify the person in their statement.

Despite not starting a game for the Cowboys, Barber was named to the Pro Bowl in 2007, despite the team finishing with the best record in the conference. He had 975 yards rushing and 10 touchdown for the Cowboys.

He spent a year with the Bears after he was released by the Cowboys. He had 4,780 yards and 53 touchdown in 99 games. He caught 179 passes for 1,330 yards and six touchdown.

His hard-charging style earned him the nickname, "Marion the Barbarian", and he was a fan favorite.

He was taken in for a mental-health evaluation by the police after he retired. He was arrested on two counts of criminal damage.