Ex-Indianapolis Colts fullback Roosevelt Potts was sentenced to 2 years in prison for a domestic violence incident in which he slashed a woman with a knife ... but he likely won't spend another minute behind bars. 

The story is pretty crazy ...46-year-old Potts -- a pretty solid player back in the '90s -- was found guilty of domestic battery by means of a deadly weapon over a 2016 incident at his Indiana home. 

Officials say the victim had two stab wounds on her shoulder following an altercation with Potts. 

The woman told police she had grabbed a knife to slash Roosevelt's tires -- when he grabbed a knife of his own and cut her up. 

Potts says the allegations are BS -- claiming the woman had gone after him with a knife and got cut as he tried to wrestle it away from her. 

The case went to trial and Potts was found guilty of domestic battery. He was sentenced to 2 years in prison -- but that sentence is suspended with the caveat that he must complete 18 months of probation without a problem. 

If he screws up, the judge can force him to serve out the prison sentence.