The feisty Russian has reached three of the last four finals at Melbourne Park, outplayed by Novak Djokovic in 2021 before a heart-wrenching defeat to Rafael Nadal a year later.
He imploded against Sinner last year, crashing in five sets after being two up.
Medvedev delayed his arrival in Australia this year due to the birth of his second child and he has not played since the ATP Finals in November.
But the world number five said it had only given him more time to prepare.
“I don’t want to make like too big of a statement, but I felt like it was one of the best pre-seasons I made,” he said.
“I feel great, because it gave me extra time to practise. I think we’re going to see a lot of interesting things from me, and I’m looking forward to it.”
The 28-year-old, whose only major success was the US Open in 2021, failed to win a title last year as Sinner and Alcaraz became the Grand Slam kings.
But he is ready to step up his game and take the challenge to them.
“Last year, except the Australian Open, I was less of a disruptor because Carlos and Jannik were beating me a lot of times,” he said.
“A lot of tournaments I was getting to the good stages but not able to beat them.
“I would like to become again … let’s say a disruptor, because it means that I will be able to get to these later stages and win them.
“At this moment they’re clearly the favourites, and that’s normal. I try to develop something (in the off-season), and let’s see if it works.”
Medvedev will open his campaign against Thai wildcard Kasidit Samrej.
© 2025 AFP