The ex-San Diego Chargers and Washington State player has served more than two years in prison after breaking into a home near Great Falls in 2012 to steal prescription pills.
The Montana conviction violated his probation in Texas on 2008 charges of fraudulently obtaining a controlled substance. A Texas judge earlier this month sentenced Leaf to five years, but gave him credit for time served.
Montana Board of Parole and Pardons senior parole analyst Julie Thomas says the board's decision Tuesday means Texas authorities can extradite Leaf if they choose.
If not, Leaf will likely be placed under a parole plan under the supervision of both Montana and Texas.