The creative midfielder has not played since the 2-2 draw with Juventus on July 11, missing the last portion of the Serie A season and their Champions League quarter-final with PSG.
He returned home to Slovenia circa six weeks ago to deal with personal issues and has been suffering from depression.
According to Tuttomercatoweb, Ilicic stepped back into the Zingonia training ground today and smiled as he saw the banners of support placed on the gates by Atalanta fans.
It’s not yet clear when he’ll be back in action, but he is expected to gradually pick up the pace of training.
“Ilicic is getting professional help, but he still has these feelings of strong anxiety, so it will take some time,” Slovenian Federation President Radenko Mijatovic told Fuzbal.