ENGLEWOOD, Colo. (AP) — Tom Heckert, a former personnel executive for the Denver Broncos who also served stints as general manager for the Cleveland Browns and the Philadelphia Eagles, has died following a long illness, the Broncos said. He was 51.

Heckert stepped away from the Broncos after last season after being diagnosed in recent years with amyloidosis, a rare disease that causes a buildup of amyloid proteins in the heart, kidney, liver and other organs. He died Sunday night.

Heckert spent 27 years in the NFL, including the last five in the Broncos’ personnel department. He was the teams’ director of pro personnel from 2013-16 before becoming senior personnel adviser in 2017.

“Tom was an integral part of our organization and we’re all incredibly saddened today,” general manager John Elway said in a statement. “With his many years of experience and time as a GM, Tom was a tremendous resource and a key member of our team. He was a very good evaluator. He had an eye for talent, and we always trusted his voice.”

Before coming to Denver, Heckert was the general manager for the Browns (2010-12) and the Eagles (2006-09).

“We are saddened to learn of Tom Heckert’s passing,” Eagles owner Jeffrey Lurie said in a statement. “Tom gave everything he had to this organization for nine seasons and played a major role in the construction and success of our team during that time. In addition to being a talented evaluator and respected voice, he was a mentor and friend to so many within our organization and around the league. He will be greatly missed by all who knew and worked with him and our hearts go out to his family during this difficult time.”

The Eagles went to the playoffs seven times in Heckert’s nine seasons in Philadelphia, winning five NFC East titles, making five appearances in the conference championship and reaching one Super Bowl.

“Tom came to Philly in 2001 and made an instant impact on and off the field,” Eagles GM Howie Roseman said in a statement. “He hired great people and his legacy is seen throughout the league in high-ranking front office positions and how many people today are talking about him and telling Heckert stories.”