Weiss' agency, Dynamic Sports Group, announced the heartbreaking news on Monday afternoon .. saying in a statement that Weiss "will be greatly missed."

According to NFL Network reporter Tom Pelissero, Weiss had been in a lengthy battle with cancer before his passing.

"Cameron was a remarkable individual who touched and impacted the lives of so many," Dynamic Sports Group leaders said in their statement. "His dedication, passion, and unwavering commitment to his family, friends and clients will always be remembered."

The group added, "Moving forward at Dynamic Sports Group, Cam's legacy will live on as we continue to serve our family of clients and he would have."

Ekeler mourned Weiss' death on social media ... writing in a comment, "He will always be a part of my story."

"Rest in piece brotha."

In addition to Ekeler, Weiss represented a bevy of other NFL players in their pursuits of contracts over the past few years ... including Eagles tailback Boston Scott and former Dallas Cowboys pass rusher Michael Sam.