The moves for Saturday's 3:30 p.m. home game against Auburn follow the season-ending knee injury suffered by starting defensive end Bruce Adrine last week and a knee sprain that threatens the status of defensive lineman Josh Mallard for the game.
"We've got to take it one day at a time, but this probably may end up being the answer for the remainder of the season,'' Garner said after Wednesday's practice. "We feel we're doing what's best for the program.''
Pollack, from Shiloh High School, has seen his playing time increase during the season as he emerged as the top freshman on the defensive line. He has 23 tackles in a backup role.
"Hopefully, I can make some plays and stay in that starting spot,'' Pollack said Wednesday.
Sullivan, who saw limited time at end as a true freshman last season, has 30 tackles, two quarterback sacks and 11 quarterback pressures this year.
"No one will question whether Johnathan Sullivan will be a good defensive end,'' Garner said. "That's a given.''
Sullivan admitted he would rather remain at defensive tackle.
"Right now I've got to do what helps the team,'' Sullivan said.
Sullivan will play at the Buck defensive end, which lines up on the side with the tight end. Charles Grant will start at the other defensive end.
With Pollack starting, Georgia is counting on Ken Veal — who has been slowed by a neck injury — serving as the top backup at defensive tackle. Veal practiced Wednesday. The other top backup on the interior defensive line is expected to be Shedrick Wynn, who has played in only four games.
If Mallard is able to play, he likely will see time at tackle instead of end. Mallard was able to run some Wednesday but still is listed as questionable for Saturday's game against Auburn.
"We're wounded right now,'' Coach Mark Richt said Wednesday. "We've got to have guys step up at all positions.''
Georgia had considered moving to a 3-4 alignment with only three defensive linemen, but Richt said "it's too drastic of a change.''
Richt said running back Musa Smith looked rusty Monday but "has done better'' the last two days. "He was moving better (Wednesday),'' Richt said. "Musa will play.''
Smith, battling a groin injury, was held out of practice last week after having only four carries in the Oct. 27 loss to Florida.
Richt named captains for the Auburn game: center Curt McGill, offense; linebacker Boss Bailey, defense; rover Jermaine Phillips, special teams.
Charles Odum can be reached at CEOdum@aol.com.