Wozniacki is a close friend of Williams and feels that she simply has too much on the go to even contemplate playing competitively again.
Serena Williams runs an investment company that aims to give opportunities to disadvantaged groups in a wide range of industries.
She has also spoken openly about her daughter not wanting her to return to the WTA Tour.
"I don't think so. If she plays an exhibition I think that would be lucky but I don't see her back playing on Tour... there are just so many things going on," Wozniacki told the Tennis Channel.
"I think she loves the game so much and it's been her life for so many years. But at the same time, she is busy. I don't think we will see her on a professional tennis court again."
Wozniacki says it isn't possible to grasp just what Serena Williams has meant to the game both on the court and off it.
"She is just a great person. She is not only, in my opinion, the greatest tennis player of all time that I have played against. She pushed me and all the other women to play better and step up," she continued.
"Also off the court, she is so thoughtful. She is the first person to call me if I went through anything to make sure I was okay. I really appreciate that."
Wozniacki says that on reflection it is amazing to have played against Serena, although when she was catching the losses she didn't appreciate the full experience.
"Playing at the same time as her was tough because there were a lot of tournaments that I felt that I could have probably won if she hadn't been in my way," Wozniacki said.
"But at the same time what an honour it has been to have been there (on the Tour) at the same time as her because I get to play against the best player that ever played this game.
"I think it was incredible to share a court with her, play against her and I have gained a lifelong friend along the way."
Serena Williams announced her intention to transition away from tennis before the US Open which so far stands as the last tournament the 23-time Grand Slam winner played in.