Earlier in March, Djokovic dropped his opener at Indian Wells, where he has won five titles, to Taro Daniel, a qualifier ranked outside the top 100.
Before that, Djokovic lost in the fourth round at the Australian Open.
“Novak remains focused and eager to come back stronger and more resilient from long injury break that has affected his confidence and game,” the website posting said. “He is continuously and passionately looking for new and different ways to regain winning form.”
Djokovic began working with Agassi on a part-time basis before last year’s French Open in May. He added Stepanek, who just retired as a player, to his team at the end of November.
Djokovic stopped working with Boris Becker in December 2016, then fired his longtime coach Marian Vajda shortly before bringing aboard Agassi.
All of this followed the most successful stretch of Djokovic’s career, which included a run of four consecutive Grand Slam titles that concluded at the French Open in June 2016. That made him the first man in nearly a half-century to hold all four major trophies at the same time, as well as the eighth man in tennis history with a career Grand Slam.
It also capped a span in which Djokovic reached the finals at 10 of 12 majors, winning six. His total of 12 Grand Slam titles trails only Roger Federer (20), Rafael Nadal (16) and Pete Sampras (14). Djokovic also has finished four years at No. 1 in the ATP rankings.
But over the past seven Grand Slam tournaments, Djokovic has zero titles and one runner-up finish. He is ranked 13th this week.
The next major, the French Open, begins in Paris on May 27.