Ireland havent ruled him and expect flanker Jordi Murphy to train on Thursday.
The Ulster back-row was pushed using a rib injury throughout the 35-0 win over Russia of Ireland, lasting 26 minutes of the victory on Thursday.
The 28-year-old had only just arrived in Japan to replace Jack Conan, who suffered a broken foot in training.
Ireland are hopeful he will be ready for Saturdays Pool A decider at Fukuoka, in which they need a victory and chose not to replace Murphy during the weekend.
He is a great deal better, a lot better than we believed he would be, said damn coach Andy Farrell.
Hes shaped up quite well. We anticipate Jordi to train on Thursday.
Weve been told he will be available to train on Thursday, thus we select our team in and around that.
Were pleased with the way Jordis hauled upward. He was pretty sore. But after all the medical advice hes been given he is in great spirits.
Joey Carbery trained fully on Tuesday, having shaken off his ankle problems back.
Following aggravating the issue which had threatened his World Cup at the first 34, the Munster fly-half was because of cover but was a late withdrawal.
Carbery had conquered that complaint to be named from the squad and suffered ankle ligament damage in the 29-10 victory over Italy of Ireland in Dublin on August 10.
But the 23-year-old endured a slight relapse to the Russia clash, raising fears of his participation.
He is flying, he is in a wonderful place, said Farrell.
Hes in the very best place I have seen him within the past couple of weeks. He ran with a spring in his step. He is in good spirits and he is ready to go.
