The league does not comment on the type of violation.

Vickerson's suspension will keep him out the rest of the regular season and started Friday with him not at practice. He will miss Sunday's game with Cleveland (4-8). He will be eligible to return on Dec. 29, a day after the Titans (11-1) conclude the regular season at Indianapolis.

The Titans declined comment on the suspension.

Vickerson's agent Tony Fleming said on Friday that it was a diuretic pill.

"Kevin is in no way admitting guilt, he simply wants to put this behind him and be ready for the playoffs," Fleming said in an e-mail to The Associated Press.

The Tennessean reported on its Web site that Vickerson tested positive for the banned diuretic Bumetanide. Five other players had their suspensions blocked Friday by a Minnesota judge after they sought a restraining order in federal court.

The 6-foot-5, 305-pound Vickerson is a three-year veteran who started his career in Miami as a seventh-round draft pick in 2005. He signed with Tennessee as a free agent in 2007 and played in four games.

He has played in seven of the first 12 games and has 1 1/2 sacks. He has 23 tackles, including one for loss, with four quarterback pressures.

The NFL Players Association filed its lawsuit Thursday to block the suspensions of Kevin Williams and Pat Williams of the Minnesota Vikings, and Charles Grant, Deuce McAllister and Will Smith of the New Orleans Saints. They were suspended four games each for testing positive in training camp for Bumetanide, which can be used as a masking agent for steroids. The drug was in a dietary supplement, StarCaps, that did not list the diuretic as an ingredient.

The union has argued the NFL didn't properly inform players about the substance. The NFL's attorneys argued that claim, and others, had been considered and rejected in a process set out by the league's collective bargaining agreement.