The Swiss star has been sidelined since Wimbledon previous year, having undergone surgery in August.
Speculation about his fitness intensified after he pulled out of Wednesday's Tie Break Tens fast-format exhibition event at Melbourne Park.
"No, for sure, it was already a tough, tough, tough moment for myself, to be out, to get surgery, to know that it will take at least six months to be back at a place where I can play tennis again", he said in Melbourne.
He wanted to spend more time with his family, but it didn't go down well with Wawrinka who has not played competitively since Wimbledon in July and is gearing up for the Australian Open next week.
"It's a good place to start, to get pushed, to see also mentally how I'm going to react, how I'm going to feel when I'm going to be playing matches".
"The knee is getting way better (but) I still have a lot of work to do physically and also tennis-wise to be to my top level", he said. I know I need to get through those. He remains in touch with his surgeon back in Switzerland to provide feedback on his progress: "He always told me that it was a big surgery, that it was a complicated one, and it was important to take the time, not to rush, really follow all the process to get there". It was tough to know that he will not be here to start again with me. I think here was a good start.
"There's always a little risk, for sure, especially starting after six months in a match, you going to get more tight, you going to get nervous, you're not going to feel as comfortable in a match as in practice".
Wawrinka, seeded ninth in Melbourne, said he had practised for more hours in the week leading into the grand slam than he had in months but still needed to be "careful" about his knee.
"That's what I want to keep from our relationship", said Wawrinka, who was the world number 17 and had never reached a Grand Slam semi-final before the pair hooked up. "But I'm happy with the way the knee is handling". "That's why I waited until the last minute to decide if I was going to play or not", Wawrinka said.
"But the knee is staying there, so that's the most important".