The number two seed takes on fellow American Brian Vahaly in the first round in Melbourne on Monday fiercely determined to exorcise the demons of last year, when Agassi pulled out of the season-opening grand slam with a wrist injury.
"Last year was a long year and Andre was playing catch-up (after) the wrist injury. But his preparation for the Australian Open started the moment he lost in Shanghai," said Cahill, recalling the Tennis Masters Cup in November.
"He is fitter than I have ever seen him and probably faster around the court. He is incredible."
The 32-year-old Agassi has already sent a warning to world number one Lleyton Hewitt, beating Frenchman Sebastien Grosjean 6-2, 6-3 to win the Kooyong Classic warm-up event on Saturday.
"Andre was very pumped up at Kooyong and the last two times he won there he won the Australian Open. That's a pretty good record," said Cahill.
TIGHT RACE
Cahill tipped Agassi and Hewitt to reach the final in Melbourne on January 26 and predicted another tight race for the year-ending number one spot in 2003.
"Andre
Agassi, who stepped up his already punishing training regime over Christmas in preparation for the Australian Open, won here in 1995 and then back-to-back in 2000 and 2001, the last time he tasted grand slam success.
"Andre peaked at the U.S. Open with that great match against (Pete) Sampras. He had a great year last year but no grand slam title. This time he feels ready," said Cahill.
Agassi will be desperate to end that particular drought and win an eighth grand slam singles title after losing to Sampras in the U.S. Open final.
All roads are likely to lead to Hewitt, but Agassi is not about to flinch, according to Cahill.
"He has found his game and he still believes he can be the best and finish at number one," he said.