The Serbian is now due to contest both the Tie Break Tens at Melbourne Park on January 10, and the Kooyong Classic, an invitational competition staged at the former home of the Australian Open.
He pulled out of last week's Mubadala WTC exhibition in Abu Dhabi only hours before his match with Spaniard Roberto Bautista Agut when the pain in his right elbow flared up and also withdrew from the Qatar Open in Doha.
"After the two events, a decision will be made about his participation at the first Grand Slam of the season, the Australian Open, where Novak has been crowned champion six times".
After competing in Abu Dhabi I realised that although I am super close, I'm not where I personally want to be.
The 36-year-old, who won last year's trophy while eight months pregnant, has played just one match since the birth of daughter Alexis Olympia.
Novak Djokovic has added the Kooyong Classic to his schedule as the former world number one attempts to prove his fitness ahead of the Australian Open.
"My coach and team always said, 'Only go to tournaments when you are prepared to go all the way.' I can compete - but I don't want to just compete, I want to do far better than that and to do so, I will need a little more time".
"Serena transcends the sport in the way she approaches all aspects of her life and consistently gives her all in everything she does".
"We all wish her the very best and I look forward to seeing her back on court this year, and can't wait to welcome her back to the Australian Open in 2019".
Williams is the latest big name to withdraw from the year's opening grand slam, which will be played from Jan. 15-28, with Britain's Andy Murray (hip) and Japan's Kei Nishikori (wrist) having already said they would not compete.