Ireland fly-half Joey Carbery has returned home after picking up an ankle injury in Saturday's win over the USA.
Carbery is set for four to six weeks rehab having flown home from New York on Sunday, with the rest of the squad heading onto Japan.
The other fly-half options in the squad include Paddy Jackson, expected to start this weekend, while Rory Scannell and Garry Ringrose are also able to cover the goalkicking.
Carbery, 21, struggled early on as Ireland went on to win comfortably in New Jersey.
"As far as I know it’s not related to the syndesmosis injury he had earlier in the season," Ireland skills coach Richie Murphy told the Irish Independent.
"It’s a grade 2/3 high ankle sprain, and we won’t be bringing anyone else into the squad. Obviously Paddy Jackson is here already so he can come straight in. We’re well covered for goal-kicking.
"Rory Scannell has been working away at that and Garry Ringrose has been doing a little bit as well, which he hasn’t done in a long time. We’re comfortable enough with the guys we have there now."