Ex-NFL Star Robert Smith, 'Today Marks 7 Years of Sobriety'

Ex-NFL running back Robert Smith is celebrating 7 years of sobriety -- which is amazing -- but he knows he's gotta stay focused so he doesn't relapse again.

"I am an alcoholic- I always have been and always will be," the former Minnesota Vikings star said in a candid social media post.

"It's not my fault, but it's my problem. Today marks 7 years of sobriety but that can change if I believe for a second that I'm different from every other alcoholic. I'm grateful I know that today. One day at a time."

Smith was a BEAST on the field -- he rushed for more than 1,000 yards in each of his final 4 seasons before retiring at 28 after the 2000 season.

The 47-year-old has been open about his struggles with alcohol -- saying he knew he had substance abuse issues back in high school but thought he could control it.

Smith has admitted he would drive drunk and show up to the Vikings practice facility "stinking like alcohol" ... but somehow managed to hide his problem from team officials.

Smith says he bottomed out after retiring -- and tried to get sober in 2007 before relapsing in 2011,

That's when Smith hit rock bottom ... his wife (who was pregnant) moved out and threatened to leave him ... and that's when he decided to make sobriety the highest priority.

Now, Smith says he's been clean for 7 years and he clearly understands what's at stake if he falls off the wagon.