India have rested key players for their final ODI against Australia on Wednesday, with skipper Rohit Sharma saying he wants everyone "fresh" for the upcoming World Cup.

Rohit and star batsman Virat Kohli return for the third ODI in Rajkot after India clinched the three-match series in the second game. They had both been rested for the first two games

Shubman Gill has been rested for Wednesday's match, while Mohammed Shami, Hardik Pandya and Shardul Thakur have all gone home. Axar Patel is still recovering from a hamstring injury.

Asian champions India, led by stand-in-skipper KL Rahul, won the first match and then hammered Australia by 99 runs to take an unbeatable 2-0 lead.

"We have got only 13 players to choose from and there is a bit of viral (sickness) going around in the team," Rohit told reporters on the eve of their last ODI before the World Cup starts October 5.

"For the next few weeks it's important to look after the players and their well-being. We want everybody to be fresh for the World Cup."

India were crowned Asia Cup champions after crushing Sri Lanka in the final, and the win over Australia took them to the top of the ODI rankings.

"I am very happy with the last 10 ODIs we played, a lot of guys came into form scoring lots of runs and the bowlers taking lots of wickets," Rohit said.

"In the last few games, guys who came back from injury have proven their fitness."

Senior spinner Ravichandran Ashwin took three wickets in the second match against Australia in Indore on Sunday.

Ashwin has been widely reported in Indian media as Patel's likely replacement in the World Cup squad.

Rohit praised Ashwin but did not commit to any team changes, with the squad able to be changed until Thursday.

"Ashwin has got the class, he has got the experience of playing the sport and handling the pressure," Rohit said.

"It's just that he hasn't played many ODIs in the last year or so. In the last couple of games we saw how well he bowled. He has got a lot of variation up his sleeve," he said.