Ed Joyce is out of Ireland's one-day internationals against Australia and South Africa as he requires surgery on a knee injury.
The 38-year-old will be replaced in the squad by Leinster Lightning batsman Sean Terry, who made his international debut during the summer series against Afghanistan.
Meanwhile, Tim Murtagh will join up with the rest of the squad in South Africa after being granted special dispensation to play for his club Middlesex in their final match of the season.
The London side take on Yorkshire on Tuesday, knowing victory will ensure their first title in 23 years.
While the rest of the Irish squad fly out on Saturday, Middlesex have agreed to fly Murtagh out as soon as their game finishes, in time for him to join the squad ahead of the first ODI against the hosts on 25 September.
