DALLAS (AP/CBSDFW.COM) – Former Dallas Cowboys running back Ron Springs, who spent the past four years in a coma after losing oxygen during a 2007 operation, has died at age 54 without ever regaining consciousness.

Since 2007, Springs had been in a coma after surgery to remove a cyst from his forearm went awry. He was considered brain impaired but not brain dead. He was diagnosed with diabetes in 1990 and received a kidney transplant in 2007.

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Former Cowboys teammate Everson Walls, who donated a kidney to Springs for a transplant, says the Springs family informed him that his friend died about 4:30 p.m. Thursday at Medical City Dallas hospital.

The hospital is where Springs first slipped into the coma after undergoing the cysst surgery.

Walls and Springs started the Gift For Life foundation after the kidney donation.

CBS 11 spoke with Walls Thursday night, who confirmed his friend and former teammate had passed away.  “I was shocked… We were hoping he would be able to come out of this.  His family is very spiritual, and they truly believe he is in a better place.”

Walls says Springs’ death will bring renewed attention to organ donation and the problems associated with diabetes.

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Cowboys owner Jerry Jones emailed a statement to CBS 11:

Ron’s life will always be remembered by the joy and laughter that he brought to others and the courage and toughness he displayed until the end.  Regardless of the circumstances, he always had a smile for everyone.  The Dallas Cowboys have lost a wonderful member of our family, and we share our thoughts and prayers with his family.

Springs attended Coffeyville Community College in Kansas before transferring to Ohio State, where he played three seasons (1976-78) for coach Woody Hayes, becoming a captain his senior year.

He led the Buckeyes in rushing with 1,166 yards in 1977 and ranks 18th all-time with 2,140.

The Cowboys drafted him in the fifth round, and he played six seasons in Dallas — mostly as a blocking fullback for Tony Dorsett — and two in Tampa Bay.

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Springs is survived by his wife, Adriane, and his son, Shawn. Shawn Springs was a cornerback for Ohio State in the 1990s and is an NFL free agent who played last season for the New England Patriots.