Oliver Jager played for Blackrock College before moving to New Zealand
The Lions play the first game of their ten-match tour in New Zealand next weekend.
New Zealand Provincial Barbarians will be the only invitational side the Lions play on the tour, and they will have an Irishman in their ranks.
Coach Clayton McMillan revealed his final 23-man squad on Thursday night and Canterbury prop Oliver Jager has been included. The 21-year-old moved to New Zealand in 2013.
Jager played for Blackrock College as a back-row forward, but moved up to the front row when he moved to New Zealand. The former Ireland schools player is now qualified by residency to play for New Zealand.
Having moved through Canterbury's ranks, he made his Super Rugby debut earlier this year. Jager could play a second time against the Lions next month when they play the Crusaders.
North Harbour's Bryn Gatland was also named in the 23-man squad. The 22-year-old fly-half is the son of Lions coach Warren Gatland.
The Lions travel to New Zealand early next week before Saturday morning's match in Whangarei. With five Leinster players in the squad including two props, Jager will be sure to know some of the opposition.