The Atlanta Falcons may be without their running back who has accounted  for 310 all-purpose yards and four TDs this season.

Former Indiana Hoosier Tevin Coleman told’s Vaughn McClure that he may not play when the Falcons take on the Broncos on Sunday in Denver due to a sickle cell trait.

From the interview, this is what Coleman had to say:

“With my sickle cell, I have no idea if I’ll play there,I really don’t know how I’ll feel or how it will be like. I’ve never been to Denver.

It does make me scared a little bit, a little nervous, because I’m risking my life, We’ll have to see. I’ll have to talk to coach (Dan Quinn). I guess coach will see how I feel when we get there. And I just have to communicate with him, if I am out there (playing), if I’m dead (tired) or can’t breathe. We just have to play it smart.”

The sickle cell trait is an abnormality with red blood cells that can be affected by high altitudes. In 2011, Pittsburgh Steeler Ryan Clark sat out when his team traveled to Denver because of potential risks.

Right now, Coleman is still uncertain if he will play on Sunday. Atlanta will enter the contest 3-1 while Denver is 4-0.

Coleman ran for 3,219 yards and 28 TDs in three seasons at Indiana. He rushed for 2,036 yards and 15 scores in his junior year before declaring for the NFL Draft. He was a third-round pick in the 2015 draft.