The St. Louis Rams running back was absent for Tuesday morning's practice. It's the 16th workout he's missed in training camp and the 12th day of camp for which he hasn't been present.
If Jackson's holdout creeps into the regular season, he must report no later than between the eighth and ninth regular-season games to fulfill his contract. At that point, he would be eligible to hit the market as an unrestricted free agent in March 2009.
Jackson was nowhere to be found at Concordia University, where the Rams are training, on Tuesday.
Information from The Associated Press and ESPN.com NFL writer Mike Sando was included in this report.