The Minnesota Vikings WR turned himself in to authorities in Arizona on Monday to begin his new sentence for violating the "no-alcohol" part of his house arrest stemming from a '16 DUI.

Floyd was booked on Monday -- posed for cop cam -- and was released on Tuesday.

As we previously reported, Floyd was sentenced to 1 day in jail and 5 more days of house arrest for the alcohol violation that Floyd blamed on Kombucha ... a fermented tea which contains a very small amount of alcohol.

Now that Floyd's out, he remains on house arrest for the rest of the week -- and must follow the rules or the judge will throw his ass right back in jail.