Novak Djokovic is preparing to take part in the Madrid Open, with the 24-time Grand Slam winner set to face Matteo Arnaldi in the first round on Saturday

Retired tennis legend Andy Murray has joined Djokovic's coaching team since November, aiming to assist his former adversary in regaining his top form. READ MORE: Shaun Murphy reveals snooker rival with the shortest fuse and admits 'he's the last person you'd want to wind up'

Novak Djokovic was left furious with himself in an angry Madrid Open practice session with coach Andy Murray before his opening match. The Serbian tennis legend locks horns with Italian world No.44 Matteo Arnaldi in the second round on Saturday at the Spanish clay-court event.