Marion Barber III, who is fourth in franchise history with 47 rushing touchdowns - died at 38
Barber played a final season with Chicago in 2011. He had issues with mental health after his career.
Police in the Dallas suburb of Frisco said - an apartment “believed to be leased” by Barber and were investigating an unattended death there.
The Cowboys, were “heartbroken by the tragic death of Marion Barber III.”
“Marion was an old-school, hard-nosed football player who ran with the will to win every down,” the team said. “He had a passion for the game and love for his coaches and teammates.”
Barber finished with 53 overall and never had fewer than four in any of his seven seasons - he never had a 1,000-yard rushing season.
Barber had a career-high 975 yards rushing and 10 TDs in 2007, when he made his only Pro Bowl.
Three years after his career ended, Barber was detained and taken to a hospital for a mental health evaluation.