Tim Murtagh, Paul Stirling Sidelined
The Ireland squad has already arrived in Australia ahead of four matches in Australia and four in New Zealand but they will not be joined by the Middlesex pair.
Murtagh has played through the domestic season with patella tendinopathy, which has required daily treatment, and he now needs a period of rest and physiotherapy in order to be fit for the World Cup, which begins in February.
He has just finished a tough season, helping Middlesex retain their top-flight status in the LV= County Championship, taking 58 wickets in 527.4 overs at an average of 28.38.
Stirling was hopeful of joining up with the squad but has not recovered from a back injury and will remain at home.
As the squad in Australia already numbers 16, no replacements will be named for the injured pair.
The tour is part of the side's preparations for the World Cup, which will see them play the West Indies (16th February), the United Arab Emirates (25th February), South Africa (3rd March), India (10th March) and Pakistan (15th March) next year.
"While it's obviously disappointing to lose players of the calibre of Tim and Paul for the trip, this gives a greater opportunity to the current squad to play more matches and put their hands up for consideration in the final 15 for the World Cup," coach Phil Simmons said.
"We have eight games down here which will give everybody plenty of cricket to make their case for inclusion."
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