World number one Novak Djokovic has pulled out of the Western and Southern Open due to a recurring left wrist injury.
Djokovic was left in tears after suffering a shock defeat to Juan Martin del Potro in the first round of the men's singles at Rio 2016.
The Serbian alluded to health issues following his third-round exit at the hands of Sam Querrey at Wimbledon in July, but picked up a record 30th ATP 1000 title at the Rogers Cup later that month.
A five-time beaten finalist in Cincinnati, Djokovic wants to take time to rest ahead of a busy close to the year with the US Open and ATP World Tour Finals still to come.
"I am very sad to announce that I won't be able to play this year in Cincinnati at the Western and Southern Open," said Djokovic in a statement.
Sad to announce that No.1 Novak Djokovic has withdrawn from the 2016 tournament due to recurring left wrist injury. pic.twitter.com/oCds4wJJqI-- W&S Open (@CincyTennis) August 10, 2016
"I have a recurring injury that has taken its toll on my body due to a very busy and active schedule this year.
"I have played many matches and I have to take some rest in order to heal. I always have my hopes high on returning to Cincinnati and winning the only trophy I am missing in the Masters series."
Tournament director Andre Silva added: "It's unfortunate for Novak that he has suffered this injury and we wish him all the best with the recovery.
"While we will certainly miss Novak, I think the Western and Southern Open will present great opportunities to a number of players who are looking to break through at one of the biggest events during the ATP season.
"It will also be a tremendous opportunity for our fans to get to see this next generation of stars up close."