Hall of Famer and former Baltimore Colts player John Mackey died Thursday at the age of 69, reports The Baltimore Sun.

Mackey, who was the first president of the NFL Players Association, had long suffered from football induced injuries before finally succumbing to frontal temporal dementia at a Baltimore area nursing home on Thursday.

DeMaurice Smith, the current head of the NFLPA, took to Twitter to send his condolences to Mackey.

John Mackey has inspired me and will continue to inspire our players and define our institution, DeMaurice Smith said. He will be missed but never forgotten.

Mackey was inducted into the Hall of Fame in 1992 after playing nine seasons as a tight end for the Colts from 1963-1971. Mackey was known for his hardnosed style of play that quickly made him a favorite of legendary coach Don Shula.

Previous to John, tight ends were big strong guys like [Mike] Ditka and [Ron] Kramer who would block and catch short passes over the middle, Don Shula told The Baltimore Sun. Mackey gave us a tight end who weighed 230, ran a 4.6 and could catch the bomb. It was a weapon other teams didn't have.

He was named first-team All-NFL three straight seasons from 1966-68 and voted to five Pro Bowls in his career.

While Mackey certainly impressed on the field, he had difficulties getting into the Pro Football Hall of Fame, in part some believe due to his involvement with the NFLPA.

As the first president, Mackey worked hard to get extra money and benefits for the players he represented, much to the dismay of football team owners. He actually brought forth an anti-trust lawsuit against the NFL in 1972, finally allowing for players to enter free agency and be able to chose a team of their choosing.

He was the right man at the right time, former teammate and NFLPA head Ordell Braase told The Baltimore Sun. He had a vision for that job, which was more than just putting in time and keeping the natives calm. You don't get anything unless you really rattle the cage.

Due to the severity of all of the injuries sustained from football, Mackey was forced to live in expensive assisted living facilities. The facilities were far more expensive than the pension Mackey got from his time in the NFL, so the NFL and NFLPA created the 88 Plan, in honor of the number Mackey wore for the Colts.

The plan pays for assisted living facilities and/or nursing homes for former NFL players suffering from Alzheimer's or other forms of dementia like Mackey.