Collymore missed their opening defeat to Australia as well as the Duckworth-Lewis victory over India on Thursday because of a right thigh muscle injury.
With West Indies needing a victory to boost their hopes of reaching the final, Collymore is anxious to return. A decision will be made on the morning of the match.
"With treatment over the past week it has been improving well," said Collymore.
West Indies skipper Brian Lara said after the victory over India that Collymore was their best bowler and crucial to his side's hopes of winning the tournament.
Australia, meanwhile, will be without their new bowling sensation Mitchell Johnson, who took four wickets against India on Saturday only for the match to be abandoned because of rain.
Johnson, Mark Cosgrove and Phil Jaques were due to return to Australia on Sunday, leaving captain Ponting with a 15-man squad for their remaining matches.
"This was a decision we made before coming out here," said Ponting. "We arrived with an 18-man squad and wanted to experiment by giving everyone a chance."
Ponting is also to be rested for the match, with Mike Hussey set to take over the captaincy. Matthew Hayden, Andrew Symonds and Brett Lee will also return for Australia.
Victory for the Australians would almost guarantee them a place in Sunday's final.
Organisers on Sunday that all remaining matches would start at 1.30 p.m. local time (0500 GMT), an hour earlier than scheduled, to allow more playing time should bad weather strike again.
