New Zealand batsman Jesse Ryder will make his Ireland debut against Gloucestershire on Thursday after signing as an overseas professional.
The 22-year-old batsman from Wellington has been playing for New Brighton in the Liverpool League.
"Jesse is an exciting talent who just missed out on selection for the New Zealand World Cup squad," said Irish coach Phil Simmons.
John Mooney is unavailable for the match and is replaced by Roger Whelan.
Ireland are seeking their first win of the competition after three successive defeats which have left them bottom of the Southern Conference.
They are still without their trio of county based players, Boyd Rankin, Eoin Morgan, and Niall O'Brien.
The same squad will be used for Sunday's trophy clash with Essex which is also being played at Clontarf.
Ryder has scored 2,344 runs in 36 first class matches. He bowls medium pace and is regarded as a natural replacement for Andre Botha who sustained a finger injury in the defeat to Somerset.
Ireland squad: T Johnston (cpt), J Bray, K Carroll, P Gillespie, N Hayward, D Langford-Smith, K McCallan, K O'Brien, W Porterfield, J Ryder, A White, R Whelan, G Wilson.