Ireland expect flanker Jordi Murphy to train fully on Thursday and have not ruled him out of Saturday's crucial World Cup clash with Samoa.
The Ulster back-row was forced off during Ireland's 35-0 win over Russia with a rib injury, lasting just 26 minutes of the bonus-point 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 opted not to replace Murphy over the weekend and are now hopeful he will be ready for Saturday's Pool A decider in Fukuoka, in which they need a bonus-point victory to secure a place in the quarter-finals.
"He's a lot better, a lot better than we thought he would be," said defence coach Andy Farrell.
"He's shaped up really well. We expect Jordi to train fully on Thursday.
"We've been told he'll be available to train on Thursday, so we select our team in and around that.
"We're happy with how Jordi's pulled up. He was pretty sore after the game. But after all the medical advice he's been given he's in great spirits."
Joey Carbery trained fully on Tuesday, having shaken off the recurrence of his ankle problem.
The Munster fly-half was due to cover scrum-half from the bench against Russia, but was a late withdrawal after aggravating the ankle issue that had threatened his World Cup in the first place.
Carbery suffered ankle ligament damage in Ireland's 29-10 victory over Italy in Dublin on August 10 and had beaten that complaint to be named in the original 31-man squad.
But then the 23-year-old suffered a minor relapse in the build-up to the Russia clash, raising fears of his further participation.
"He's flying, he's in a great place," said Farrell.
"He's in the best place I've seen him over the last few weeks. He was running around with a proper spring in his step. He's in great spirits and he's ready to go."