Calipari wasn't specific about the type of injury.
A senior starter, Poythress sat out Saturday's win over Florida because of soreness in the knee; Calipari said he found out "about five minutes" before tipoff that Poythress tweaked his knee and couldn't play.
Poythress had swelling on the knee, but an X-ray didn't show anything, according to Calipari, and Poythress was considered day-to-day heading into Tuesday night's matchup. He did not play against the Bulldogs.
Poythress, who is averaging 10 points and 6.6 rebounds, had played in all 22 of No. 22 Kentucky's games to start the season before sitting out the past two. He scored a career-high 25 points in a 77-61 win at Alabama last month.
Poythress has dealt with knee ailments before. Last season, he tore the anterior cruciate ligament in his left knee, which forced him to miss the final 29 games.
Information from The Associated Press was used in this report.