Defensive lineman Ron Brace, a 2009 second-round draft choice of the New England Patriots, had died at the age of 29.
Brace's death was confirmed by the Springfield (Massachusetts) Police Department, which said an investigation is ongoing.
The cause of death is not suspicious, Springfield Police Captain Robert Strzempek told MassLive.com.
"We were deeply saddened to hear the news this morning of Ron Brace's death," the Patriots said in a statement. "Seven years ago tomorrow, we drafted Ron after his standout career at Boston College. During his Patriots career, the Springfield native was always eager to volunteer and give back in our communities, especially when those community initiatives were held in Western Mass.