The 22-year-old joined Championship outfit Forest on loan from Premier League club Villa in the January transfer window.
With the Reds playing their last game of the 2014-15 Championship campaign tomorrow, Gardner will return to his parent club next week.
The youngster has been an important player for Dougie Freedman’s side and has done quite well.
In 17 Championship appearances, Gardner has scored four goals and created 10 chances, while having a pass accuracy of 73% and a shot accuracy of 29%.
The midfielder has won 51 headers, six dribbles and 46 tackles in those 17 league matches.
Gardner has also made himself a popular figure among the Forest fans, and he has admitted that he is “emotional” to be leaving the City Ground.
Last game of the season tomorrow it's going to be emotional#nffc— Gary Gardner (@22Gards) May 1, 2015
Forest will end their season with a home game against Cardiff City tomorrow. The Reds are currently 12th in the Championship table with 59 points from 45 games.