Univ. of Tennessee -- 9 Football Players Busted ... At Insane House Party Gone Wrong

Nine members of the University of Tennessee football team were busted at a HUGE team rager over the weekend ... with booze, weed and FIGHTS, this according to the cops.

TMZ Sports has learned ... cops initially responded to an off-campus party in Knoxville just after midnight on Sunday morning after getting noise complaints. Cops say the party was hosted by Dontavis Sapp -- a former UT linebacker.

Cops say they went to talk to Sapp ... but he was clearly wasted ... and they tried to take him into custody. That's when, cops say, senior linebacker AJ Johnson stepped in ... and grabbed a cop by the shoulder, in an effort to keep Sapp from being arrested.

Johnson was "pulled to the ground" by one of the cops who says the football player "continued to resist arrest by pulling away and rolling around."

Cops say .... another player, 20-year-old defensive lineman Danny O'Brien, was also hammered and combative and was taken into custody "after a brief struggle."

Cops cited 3 other football players -- Curt Maggitt (LB), Jakob Johnson (LB) and Jalen Reeves-Maybin (LB) -- who allegedly provided booze and weed to underage party guests, including:

-- Dontavius Blair (OL)
-- Dimarya Mixon (DL)
-- Justin Coleman (DB)
-- Malik Brown (DL)

The 4 players were cited for underage drinking.

A spokesperson for UT tells us ... "We are aware of the situation and are still in the preliminary stages of gathering all facts and information."