Frances Tiafoe cursed out the umpire over a serve clock rule violation during a critical juncture in his match. Once again, the serve clock became an issue at the same tournament today. Novak Djokovic had no trouble defeating Roman Safiullin in straight sets: 6-3,

The Serbian champion, in the match won against Roman Safiullin, spoke with chair umpire Ignacio Forcadell expressing his disappointment with the new rule

Novak Djokovic is the latest tennis player to express his frustration with the implementation of the serve clock rule in tournaments this season. Tennis players now have 25 seconds from three seconds after the previous point to serve the next point.

The 24-time Grand Slam champion has been left frustrated by a rule change that was introduced earlier this year but has only impacted him for the first time this week

Novak Djokovic has become the latest player to take issue with the new automated shot clock. The 24-time Grand Slam champion claimed the tour changed the rules mid-season without informing players. Since June,