Former Houston Texans and Philadelphia Eagles linebacker Bryan Braman is undergoing treatment for a rare, aggressive form of cancer, with his longtime agent describing the situation as extremely serious.

Braman, 38, has had multiple surgeries while being treated in Seattle, according to a GoFundMe page set up to help him with expenses. Braman was diagnosed with cancer in February.

“At Stellato Sports, Bryan Braham has always stood for strength, resilience and leadership,” Braham’s agent, Sean Stellato, told KPRC 2 in Houston. “He is a pillar and a staple of the underdog.

“Now, in the face of cancer, he embodies those qualities more than ever. If there is one person that I know that can beat cancer, it is Bryan Braman, who I have always considered family. He’s in the fight of his life.”

The GoFundMe for Braman has raised more than $52,000 as of Saturday morning, with former Texans star J.J. Watt giving $10,000 and other former teammates also contributing.

Braman played seven seasons in the NFL from 2011 to 2017. He won a Super Bowl with the Eagles after joining the team for the playoffs, blocking a punt in the divisional round. The Super Bowl LII victory was Braman’s final NFL game.