Ireland's Rob Kearney has been passed fit to face Scotland in Sunday's World Cup encounter, but Robbie Henshaw will definitely miss out.
It was feared that Kearney would miss the game was after picking up a calf injury in training on Monday.
Backs Keith Earls and Joey Carbery have both trained after sustaining injuries in warm-up fixtures.
Henshaw, who injured his hamstring in training on Saturday, will not recover in time for the game in Yokohama.
However, it is hoped the Leinster centre will be fit for for Ireland's second Pool A game against hosts Japan.
"Robbie won't make this weekend," said defence coach Andy Farrell. "We are very happy with his progress but he will sit out this weekend and hopefully he will be available for next week.
"We're pleased with how things have gone today. Rob and Keith ran well, and trained well.
"There's a few protocols that they need to go to, so that's what we need to adhere to with the medical staff. But they are very happy."
Kearney pulled up in training on Monday, which put "significant doubt" over his selection for the fixture.
Carbery was forced off against Italy in the opening warm-up game but has recovered from an ankle injury and is expected to take a place on the bench.
Likewise, Earls is available after shaking off a thigh complaint picked up at home to Wales.
Ulster's Will Addison remains on standby after the injuries to head coach Joe Schmidt's backline, with Ireland management requesting that the full-back was rested from Saturday's pre-season friendly against Glasgow.
Kearney impressed in Ireland's 19-10 victory over Wales that closed their World Cup warm-up fixtures in Dublin on 7 September.
The 92-cap full-back ties Ireland's backline together and Schmidt will be keen to have his calming presence in the key pool match.