Police said no further details would be released pending the “ongoing” investigation and the official cause of death will be determined by the Collin County Medical Examiner’s Office.
The Cowboys’ training facility is in Frisco. Police identified Kneeland as a resident of Plano.
The Cowboys did not provide details about Kneeland’s death earlier on Thursday.
“It is with extreme sadness that the Dallas Cowboys share that Marshawn Kneeland tragically passed away this morning,” the team said in a written statement. “Marshawn was a beloved teammate and member of our organisation. Our thoughts and prayers regarding Marshawn are with his girlfriend Catalina and his family.”
Kneeland was chosen by the Cowboys in the second round of last year’s NFL draft out of Western Michigan University.
He played in 18 games and started four of them for the Cowboys over the past two seasons. Kneeland scored a touchdown by recovering a blocked punt in the end zone during the Cowboys’ 27-17 loss in the NFL’s Monday night game against the Arizona Cardinals in Arlington, Texas.
The Cowboys are on their bye this week and don’t play again until a November 17 road game against the Las Vegas Raiders.
“We are deeply saddened by the tragic news of the passing of Cowboys’ Marshawn Kneeland,” the NFL said in a statement. “Our thoughts and prayers are with his girlfriend Catalina, family, friends and his teammates. We have been in contact with the Cowboys and have offered support and counselling resources.”
Fellow Cowboys player Juanyeh Thomas wrote on social media that he was sick to “my stomach”.
One of Kneeland’s representatives, agent Jonathan Perzley, said in a statement to the NFL Network that he was “shattered to confirm” Kneeland’s death.
“I watched him fight his way from a hopeful kid at Western Michigan with a dream to being a respected professional for the Dallas Cowboys,” Perzley said. “Marshawn poured his heart into every snap, every practice, and every moment on the field. To lose someone with his talent, spirit, and goodness is a pain I can hardly put into words. My heart aches for his family, his teammates and everyone who loved him, and I hope they feel the support of the entire football community during this unimaginable time.”
The NFL Players Association said it was “working to ensure that players have the support they need”.
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