Australia have lost their last five one-day matches and received a body blow Friday when fast bowler Brett Lee was ruled out with an ankle injury.
"Australia may have lost a few matches but for me they still are the World Cup favourites," Inzamam told reporters after a training camp for next month's tournament in the Caribbean.
However, he said the defending champions' problems have opened the door to other teams.
"Australia have been winning for the last 10 years or so and they are a very consistent side but their recent defeats have given more chances to other teams," said Inzamam, 36.
Inzamam, who will be playing his fifth World Cup, said he hoped doubts over strike bowlers Shoaib Akhtar and Mohammad Asif would be resolved.
The two are both nursing injuries and are the only squad members not to undergo compulsory in-house dope tests.
Both had doping bans controversially lifted in December and face life bans if they test positive again. They must also undergo fitness tests on February 27.
"It would have been better to have a full squad confirmed rather than having fitness worries because it doesn't allow you to plan.
"But I am not thinking negatively. Akhtar and Asif are our main players and I hope they not only overcome their injuries but reports of their tests also come in our favour," said Inzamam.
Eleven of the 15-man Pakistan squad, five reserves and two extra players have passed dope tests while results for Inzamam and allrounder Shahid Afridi are expected in the next couple of days.
No date has yet been set for tests on Akhtar and Asif. Experts have warned they still have banned substance in their systems after testing positive for nandrolone last October.