Ireland Hit By Double Injury Blow
Sorensen suffered a wrist injury during the recent One-Day International series against Scotland and will be replaced in the squad by Graeme McCarter.
McCarter, who plays for Gloucestershire, made his ODI debut in the third and final match against Scotland last week.
Stirling has a back problem and will not be replaced in the squad.
As part of their preparations for the 2015 World Cup, Ireland play eight matches in Australia and New Zealand, starting on 30th September.
Scans on Sorensen's wrist revealed a fracture and he has been ruled out for between six and eight weeks.
Stirling has been referred to a specialist and his fitness will be monitored in the coming weeks.
However, Cricket Ireland remain hopeful that he may be able to feature in some part of the tour, which lasts until 23rd October.
"It's obviously bitterly disappointing for Max to miss out on the tour which is so vital to our World Cup preparations, but it gives Graeme a great chance to impress after he just missed out on the initial selection," head coach Phil Simmons said.
"Paul Stirling missed Middlesex's match at Somerset this week with a back injury which hasn't responded to treatment as well as he'd like.
"We'll know more about his prognosis when he sees the specialist, but felt it best that he recuperates in the UK before making a final decision on his involvement on the tour," he added.
Ireland will play two games apiece against Queensland Bulls and New South Wales seccond XIs before heading to New Zealand to play matches against Northern Districts, a New Zealand XI, Canterbury and Otago.
Ireland will play the West Indies in their first World Cup match on 15th February before also taking on United Arab Emirates (25th February), South Africa (3rd March), Zimbabwe (7th March), India (10th March) and Pakistan (15th March).
Ireland squad: William Porterfield, Andrew Balbirnie, Peter Chase, Alex Cusack, George Dockrell, Graeme McCarter, John Mooney, Tim Murtagh, Andrew McBrine, Kevin O'Brien, Niall O'Brien, Andrew Poynter, Stuart Poynter, Paul Stirling (subject to fitness), Stuart Thompson, Andrew White, Gary Wilson, Craig Young
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