Vajda initially became Djokovic’s coach in 2006 and the Serbian won 12 Grand Slam titles on his way to capturing the world No 1 ranking.
A nasty elbow injury required surgery last year and the pair spilt with Djokovic opting to take a new direction in his career by hiring Andre Agassi and Radek Stepanek.
But that relationship soon turned sour and Djokovic axed the duo earlier this year before asking Vajda to help him recover his form.
“I had mixed emotions when he called me because I didn’t follow his tennis for almost a year and I really wanted to be at home and spend time with my family,” Vajda told the Telegraph.
“It took me three days of talking to my family for us all to come to the decision on this.
“Then I figured out that it would be good and important for me to go back again.”
Since linking up with Vajda for a second time, Djokovic reached the French Open quarter-finals and was the runner-up at Queen’s last week.
The 31-year-old has really started to rediscover some of his best form ahead of Wimbledon which is impressing his mentor.
“I am very pleased with the way he has performed this week [at Queen’s],” Vajda added.
“This time it is nice but different.
“Novak caught me by surprise calling me up and asking me to join his team again.
“Obviously, I was very pleased to do it, but it was different because his tennis was not at the same level and you have to start over again.”