As for the game itself, Ireland struggled to overcome the enthusiastic challenge of Sanfreece Hiroshima.
Even without Keane, Ireland attracted a sell-out crowd of more than 10,000 for the friendly against J-League opposition.
McCarthy's men were briefly behind to a 37th minute header from the unmarked Kubo.
But Robbie Keane stooped to head the Irish level just four minutes later.
Stephen Reid, who replaced McAteer, took a corner from the left, Kilbane
flicked it on and Keane headed home at the far post.
And it was the Leeds star who scored a 79th-minute winner from a knock-down by substitute striker Niall Quinn.
Sanfreece Hiroshima: Ozaki, Kawashima, Sawada, Komano, Tulio, Nakamura, Bilong, Morisaki, Fujimoto, Kubo, Oki.
Republic of Ireland: Given (sub Kiely 61), Harte (sub O'Brien 45), Dunne (sub Breen 45) , Staunton, Kelly, Holland, Kilbane (sub Quinn 61), Kinsella, McAteer (sub Reid 37), Duff (sub Connolly 70), Robbie Keane (sub Morrison 80).