World No 3 Alcaraz played his last official match of 2024 at the Davis Cup, beating Tallon Griekspoor in singles action before tasting defeat in a decisive doubles rubber.
However, that was not the last time Alcaraz was seen on court this year.
The 21-year-old went to New York at the beginning of December to face Ben Shelton at Madison Square Gardens, before facing Frances Tiafoe in an exhibition match in Charlotte, North Carolina.
Having also played the Six Kings Slam exhibition in Riyadh this October, the four-time major winner has attracted criticism for playing exhibitions despite his existing complaints about the ATP schedule.
And, speaking on the Nothing Major podcast, former world No 8 Isner suggested Alcaraz could be criticised further if he were to lose early in Australia.
He said: “None of us blame Carlos for going over there and picking up two huge cheques, but Sinner seems to be laying low after his fantastic year, going back to work and keeping a low profile.
“I think they’ll both be ready for Australia, but if Carlos doesn’t have a good performance at the Australian Open, a lot of people are going to come down on him because he was in the States in December playing exhibition matches instead of preparing.
“I don’t think that’s fair, but that’s the way it’s going to be.”
