LONDON -- Seven hard-court tournaments leading up to the US Open have mirrored the Grand Slam event by adding serve and warmup clocks in an effort to speed up matches.
The U.S. Tennis Association, ATP and WTA announced Wednesday the changes to events in Washington; San Jose, California; Montreal; Toronto; Cincinnati; New Haven, Connecticut; and Winston-Salem, North Carolina. Those tournaments will have 25-second serve clocks as well as a strict, seven-minute period from when players enter a court until action starts.
The US Open made the decision in April to add these changes to all main-draw matches.
Players will have one minute from walking on court until the coin toss, five minutes for warming up and a minute from the end of the warmup until the start of play. Players who don't abide by those limits will face fines.
If the 25-second serve clock runs out, players will be issued a time violation by the chair umpire. Chair umpires will be able to pause the clock at their discretion.
Clocks will be visible on court.
The US Open is the first Grand Slam tournament to use the serve and warmup clocks.
The Associated Press contributed to this report.