French Open champion Halep warmed up for her run to the final at Melbourne Park last year by winning the Shenzhen Open in southern China but has played only one match since September, a 6-4 6-4 defeat to Australia's Ashleigh Barty at the Sydney International on Wednesday.
The top seed said her back had recovered "100 percent" from a herniated disk aggravated at the China Open in September, however, she revealed she was also feeling a bit behind the curve.
"I am motivated. But it's a little bit different because last year I had about 10, 15 matches before Melbourne, now I have only one, which I lost," the Romanian told reporters at Melbourne Park on Saturday.
"I took the risk staying home a little bit longer. I rested because I felt like I'm exhausted after those tournaments and also the year that I had.
"I enjoyed the time at home a lot. Now I feel refreshed to start the year, but still I am a little bit back with everything, preparation and matches.
"But I don't complain. Everything was how I wanted. So now I have just to put my head down and to go and work."
Her opening shift is a daunting one, against Kaia Kanepi, the same woman who knocked her out of the first round of the U.S. Open.
The shock loss to the unseeded Estonian made Halep the first top seed to fall at the first hurdle at Flushing Meadows.
Her former coach Cahill delivered the news of the re-match by text message after doing the draw at Melbourne Park on Thursday.
"You really want to know?" Halep smiled, after being asked how she reacted.
"I was at Nike taking my new shoes. When I saw the message, I was like, 'Okay, whatever. I just enjoy the moment with the shoes, then I'll think about the match'. That's it."
Cahill quit Halep's team for "family reasons" and the Romanian said she would proceed without a coach for the first few months of the season.
She was not interested in hiring coaches on short-term gigs, wanting to take time to pick the right one.
"For me it's a little bit tough to change the person I'm working every day because I get attached to the people, to my team. I cannot change fast," said Halep, a gallant loser to Caroline Wozniacki in the Melbourne final last year after carrying a painful ankle injury through the tournament.
"Every time you commit to someone in your team, you
have to give 100 percent.
"As I say always, at this level it is impossible without a coach. So maybe in the close future I will have someone. But for the moment, I'm just by myself."
(Editing by Greg Stutchbury)
