ENGLEWOOD, Colo. — 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.

"He took the time to help all of us get better and learn more about how to evaluate and build teams. His record as a GM was outstanding. When he worked here everyone wanted to be around him and listen to his stories about his time in the league and his experiences around the game. He was one of the first people to congratulate us all when we won the Super Bowl. Thoughts and prayers are with his family, including his kids."

Heckert began his NFL career in 1991 as a scout with the Miami Dolphins, who promoted him to assistant director of pro personnel/college scout in 1999 and director of pro personnel in 2000. He was hired by the Eagles as their player personnel director in 2001 and was promoted to vice president of player personnel in 2003.

His father, Tom Sr., worked for more than 20 years as an NFL player personnel executive before retiring in 2007.

His time in Denver included three playoff trips, two Super Bowl appearances and a win over Carolina in Super Bowl 50.

"It's easy to see why Tom was widely respected and had so many great relationships across the league," Elway said. "I'll always be grateful for how he helped me transition into this position. My prayers go out to Tom's family, friends and everyone he worked with during his career."

Matt Russell, the Broncos' director of player personnel, worked with Heckert in Philadelphia and Denver.

"Tom was one of the best because he combined exceptional player evaluation skills with his incredible network of connections around the NFL," Russell said. "Those relationships he formed are a testament to how well he treated everyone. Tom was a loyal friend and my heart goes out to his family."

The Browns also released a statement expressing the organization's sympathy: "We are deeply saddened by the passing of Tom Heckert and share our sincerest condolences with his family and friends, including the many lives he impacted with the Browns organization and throughout the entire NFL during his established career."