Kim Clijsters will not make her comeback at the start of next season due to a knee injury but remains as "determined as ever" to play at the highest level again.

The four-time grand slam champion sprung a major surprise in September by announcing she was coming out of retirement at the age of 36.

However, Clijsters on Monday revealed her WTA Tour return will have to wait.

"I've had to make the decision that I will not be able to compete in January. I am undergoing rehab and treatment for a knee injury," she tweeted.

"It's a setback but I'm determined as ever to get back to the game I love. I really appreciate all your support and encouragement."

The Belgian, a mother of three, retired in 2012 after winning 41 singles titles. 

Clijsters is eligible for unlimited wildcards at WTA tournaments as a former world number one, but she will have to play three tournaments or earn 10 points to re-establish a ranking.