Blackmon, who is from LaGrange, Ga., did not return for classes that began on Wednesday at Auburn. He had an injury-plagued season after beginning the year as a starter at middle linebacker for the Tigers.
Tray Blackmon is shown at a 2008 practice.
Prior to coming to Auburn, the former LaGrange High star said his plan was to go pro after his junior season. He played in just six games this past year before being shut down for the rest of the year with a wrist injury that required surgery. He finished the season with 21 tackles.
Williams played in seven games in 2007 as a true freshman and made two solo tackles with two assists. He is from B.C. Rain High in Mobile.
Another second-year player, wide receiver Chris Slaughter, is not enrolled at Auburn this semester. He did not finish the season with the team after being suspended for the Alabama game by Tuberville for undisclosed reasons.
Slaughter, who is from Peach County High in Fort Valley, Ga., caught three passes for 19 yards in 2007. This past season he caught 15 passes for 179 yards and one touchdown.
Glenda Slaughter, the wide receiver's mother said, "I don't think he is returning to Auburn. That's all I can say."
Two other Tigers announced previously they are passing up their senior seasons to enter the NFL Draft. Defensive tackle Sen'Derrick Marks is in Atlanta training for the upcoming NFL Combine. Cornerback Jerraud Powers is doing workouts with trainers in California.