Former world No. 1 Justine Henin thinks Novak Djokovic is going through a difficult period and that impacted his decision to split with his long-term coach Marian Vajda. Last week, it was announced Djokovic and Vajda were splitting after 15 successful years. Djokovic and Vajda split for the first time in 2017 but got back to working together in 2018. Djokovic enjoyed major success after returning Vajda to his coaching staff and his decision to split with Vajda again came as a surprise to many. “He is going through a difficult period. And in difficult times sometimes important decisions have to be made. I think that if there was a turning point in the months, it probably happened during the Olympics. It will have an impact in the next few weeks,” Henin told Eurosport.Djokovic and Vajda split on good terms Djokovic took to Twitter to confirm that he was indee …