The news came just ten days after Czech Republic's Stepanek bid adieu to professional tennis following more than 20 years on the ATP World Tour.
12-time major champion Djokovic and Stepanek declared that the duo has joined forces on Instagram Live.
"I'm ready to go," said Stepanek to the Serbian on the split screen as they talked to each other from their phones.
Subsequently, Djokovic quizzed, "Where are you?," before opening a door to reveal Stepanek on the other side.
He added, "All right guys, this is the new team, baby!"
Reflecting on Stepanek's appointment, former world number one Djokovic said that he was quite impressed with the Czech's level of determination and that he is quite excited to join forces with him.
"Radek is one of my very close friends on the tour and I was always impressed with his level of determination, passion and love for the sport.He has a lot of experience and knowledge, and he has played on a high level for many years. I am excited to join our forces together and cannot wait to compete again having a new team to back me up," the ATP quoted Stepanek, as saying.
The recently-retired Czech will join Andre Agassi in Djokovic's coaching team and now he will be working closely with the Serbian star in Monte Carlo who is all set for the 2018 season.
Djokovic, whose season was cut short after sustaining a right elbow injury at Wimbledon, is slated to return to action with the season-opening Qatar ExxonMobil Open in Doha. (ANI)