Wawrinka has not played since his first-round exit from Wimbledon in July, when he lost to Daniil Medvedev while clearly hampered by a knee problem.
The Swiss reluctantly underwent surgery, ending his season halfway through the year, but is scheduled to make his return to action on December 28 against Pablo Carreno Busta at the Mubadala World Tennis Championship.
But Wawrinka has admitted in an interview with Swiss newspaper Le Matin that he had battled “a general feeling” about quitting tennis altogether.
“When you go through four months of inactivity, you can not walk, you put everything in question,” Wawrinka said.
“During my first workouts, I did some walking, some steps.
“It makes sense to doubt, to lose confidence.
“I think it would have been impossible for me to live all this without someone who knows me perfectly.
“Pierre [Paganini, fitness coach] knows exactly how far I can push, what I have the right to do or not.
"He could identify each of my limits of the moment."
“His presence was a lifeline.”
Stan Wawrinka was left immobile by serious knee surgery
Wawrinka added: “The operations, the immobilize, the fact of being away from the circuit, all that weighs on the morale.
“And then you feel lonely. I was also lacking the tension, the excitement of the competition, the stress that all of a sudden no longer exists and you can not provoke."
“But from the moment I got back to work, I was confident of being able to return to a certain level."
“I do not know exactly which but certainly at a realistic level."
“That said, I could not imagine how hard this recovery process was going to be.
“The most complicated is to have to do a lot more work when in fact I do less than usual because I do not have the right.
“Mentally, I have to focus on the knee, be careful not to impose certain movements on it.
“I am also watching the rest of the body, which must gradually get used to the charges. In fact, I have to push hard but in a predefined and very rigid way.”