Former NFL player Paul Duncan, who was briefly with the Denver Broncos in 2010, has died aged 35.

As his wife Ellen Duncan confirmed on Instagram, the former offensive lineman passed on July 15.

“Paul went into cardiac arrest while on a run in our neighborhood,” she wrote. “Today he was pronounced brain dead. We will have a medical examination to understand the cause of death. His body will be donated to people in need of organs and to medical research. Details on funeral arrangements to follow. Thank you for your prayers and support.”

Per E! News, the DeKalb County medical examiner’s office in Georgia confirmed that Paul Duncan’s death is currently under investigation.

Prior to his time at training camp with the Broncos, with whom he signed as an undrafted free agent, Duncan played college football at Notre Dame from 2005-2009. In a statement, Notre Dame’s football team paid respects to him. 

“Our prayers go out to the family and friends of Paul Duncan,” its tweet read. “A great teammate, but more importantly a loving husband and father.”

Per his obituary in the Atlanta Journal-Constitution, Duncan had two daughters, 6-year-old Dillon and 4-year-old Sloane. 

"He embraced the role of 'girl dad,' from building playgrounds in the backyard to doing hair before school," reads the piece. "Dillon and Sloane loved Paul's impromptu dance parties in the kitchen and his adventures with them in the water, whether it was at the lake with family or at the pool with friends."