The one-day international series against Namibia has become a critical preparation block for Ireland ahead of next year's World Cup qualifiers.
Paul Stirling, the 36-year-old captain, confirmed he cannot participate in the concluding matches after fracturing his finger during Tuesday's third ODI.
Stirling was fielding when the injury occurred, an event that left his side trailing their hosts by two runs to one in the five-match contest.
Although unable to bat in Ireland's innings on Tuesday, Stirling had contributed with half-centuries of 56 and 77 in the opening two games played in Windhoek.
Ireland secured victory in the opener on 22 October but have since lost by 31 and 63 runs respectively in the subsequent encounters.
Head coach Gary Wilson is managing a difficult campaign as he attempts to salvage the series following this latest development.
The tournament resumes on Friday before a final fixture takes place on Sunday, with Stirling absent from both matches.
Tim Tector has been appointed as the replacement for the injured captain in the upcoming fixtures.
Tector remains uncapped in ODI cricket but brings experience through eight appearances for Ireland in T20 format where he averages 17 runs.
The younger sibling of middle-order batter Harry Tector is expected to provide depth to the batting lineup during the remaining games.
This series serves as a vital testing ground for the squad before they face the global stage next year.
No further details regarding Stirling's recovery timeline or specific return date have been provided by management yet.