It has been a patchy season by Djokovic’s high standards.
A positive start saw him reach the Australian Open semi-finals, although he had to pull out injured against Germany’s Alexander Zverev after losing the first set.
The world number six, who turns 38 this month, lost three matches in a row on his comeback before rediscovering form at the Miami Open.
However, he was overwhelmed by powerful Czech teenager Jakub Mensik in the final, costing him another chance to win his 100th ATP title.
Overall, he has won 12 of his 19 matches this season and hopes to improve that record in Geneva.
Last year, Djokovic reached the semi-finals on his first appearance in the Swiss city.
He went on to reach the Roland Garros quarter-finals, but had to withdraw from his last-eight match against Casper Ruud with a knee injury picked up in the previous round.
Norway’s Ruud, who beat Britain’s Jack Draper in the Madrid final on Sunday, is also in this year’s Geneva field, along with American world number four Taylor Fritz.
The ATP 250 event begins on 18 May, with the French Open starting a week later on 25 May.