A pair of former Carolina Panthers teammates died over the weekend.

Northern Arizona University assistant football coach Jeff Lewis, who played in seven games at quarterback for the Panthers from 1999-2000, died at age 39 of an undisclosed pre-existing condition.

Bryan Stoltenberg, an offensive lineman who played in 42 games with 18 starts for the Panthers, died at age 40. He recently underwent surgeries after a car accident in December. An autopsy is expected to reveal he died of a blood clot.

“We are very saddened to learn the news of the passing of former players Jeff Lewis and Bryan Stoltenberg,” the Panthers released in a statement. “Both men always represented the team and organization in the best possible manner, and our thoughts and prayers go to their families.”