Leinster hooker Tracy and Ulster lock Treadwell are two of six changes made by coach Joe Schmidt from last week's 50-22 victory over the host.

Devin Toner is primed to make his 50th international appearance in Tokyo, while Cian Healy will clock up his 70th.

John Cooney could make his debut after the scrum-half was named among the replacements.

A quartet of players – Andrew Conway, Rory Scannell, Luke McGrath and Dan Leavy – earned their first starts in the opening contest.

Ireland XV: Andrew Conway, Keith Earls, Garry Ringrose, Luke Marshall, Jacob Stockdale, Paddy Jackson, Kieran Marmion; Cian Healy, James Tracy, John Ryan, Kieran Treadwell, Devin Toner, Rhys Ruddock, Josh van der Flier, Jack Conan.

Replacements: Niall Scannell, Dave Kilcoyne, Andrew Porter, James Ryan, Sean Reidy, John Cooney, Rory Scannell, Tiernan O'Halloran.