PHILADELPHIA (973espn.com) - Former Eagles general manager Tom Heckert passed away on Sunday night at the age of 51.

Heckert, a former GM in Philadelphia and Cleveland, had most recently been in personnel with the Denver Broncos, who confirmed the sad news on Monday.

"Tom was an integral part of our organization and we're all incredibly saddened today," Broncos 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. It's easy to see why Tom was widely respected and had so many great relationships across the league. 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."

Heckert spent a decade in Philadelphia and was a key part of the Andy Reid era helping the Eagles reach four consecutive NFC Championship Games and one Super Bowl. He joined the organization in 2001 as the director of pro personnel, was promoted in 2003 to vice president of pro personnel, and eventually became the GM in 2006, serving four years in that role.

The Eagles finished 38-25-1 during Heckert's run as GM, making the postseason three times and the 2008 NFC Championship Game.

"Tom came to Philly in 2001 and made an instant impact on and off the field," Eagles executive VP of football operations Howie Roseman said. "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 with his family, including his kids."

After the 2009 season, Heckert went on to become the general manager of the Cleveland Browns

Heckert was recently diagmosed with a rare blood disease, amyloidosis.

"We are saddened to learn of Tom Heckert's passing," Eagles owner Jeffrey Lurie said. "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."

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen