A five-times Australian Open runner-up, Murray's career looked set to end prematurely due to a long-standing hip injury after his first-round defeat in 2019 when he received an emotional 'farewell' on the court.
But the three-times Grand Slam champion has continued to push himself after multiple surgeries and said he was not worried about being drawn against the 2021 Wimbledon runner-up.
"Obviously a tough draw, but I also feel like I'm in a much better place than where I was during any of the Grand Slams last year," Murray told a news conference on Saturday.
"I feel ready to play a top player early...whereas maybe last year at times my game didn't feel that great and getting a difficult draw or a tough match early didn't feel great. I feel I'm in a better place this time to deal with that."
Berrettini has won their previous three meetings, including a four-set victory at last year's US Open.
"Obviously the match at the US Open was close, the match we played in Stuttgart was close and I won in Beijing," Murray added. "I know how I feel today in comparison to where I felt going into the U.S. open and I'm playing better."
Fellow Briton Emma Raducanu said she was feeling good about her fitness ahead of the Australian Open after rolling her ankle in a tune-up event last week.
Raducanu retired from her second-round match at the Auckland Classic, sparking concerns she could miss the year's first Grand Slam where she will bid to add to her 2021 US Open crown.
"At the time you're a bit worried about it, when you just go over you don't know what's going on," Raducanu, who plays Tamara Korpatsch in her opener, said.
"But we've been working hard. It's been a team effort to get me to this place. We've expedited the process, but I'm feeling really good and looking forward to getting out on the court."
Raducanu said she resumed practice in midweek and was not too concerned about the shortened preparations.
"I've not really played much tennis ever in my career, so I'm used to it and not stressed about a lack of tennis that much," Raducanu said.
