The Super Bowl MVP and Johnny Football attended Texas A&M at different times but have become close.
Manziel, who won the Heisman Trophy at A&M, has had a troubled NFL career and is being investigated for domestic violence. The Cleveland Browns have indicated they will release him next month.
Miller says: ''I'm not worried. I feel like Johnny's taking care of business. He has adversity. Everybody has been here with adversity. I've been here with my own personal adversity. The support that I'm giving him is the support that he's given me in the past.''
The Denver linebacker said they text often and also talk and that wants to be there for the quarterback.
He thinks Manziel's troubles are behind him and says: ''I truly believe he's on the right track now.''